GB2343186A - Tetrasulphamoyl- phthalocyanine & naphthalocyanine dye derivatives for use in tissue demarcation, imaging, & diagnosis of tumour cells & diseased lymph nodes - Google Patents

Abstract

Compounds of formula (I) <EMI ID=1.1 HE=60 WI=103 LX=806 LY=75 TI=CF> <PC>and of formula (II) <EMI ID=1.2 HE=63 WI=108 LX=806 LY=894 TI=CF> <PC>[wherein<BR> M is a metal or metalloid;<BR> each <EMI ID=1.3 HE=13 WI=13 LX=901 LY=1656 TI=CF> <PC>is independently an optionally substituted aromatic benzene or naphthalene nucleus;<BR> each R<SP>1</SP> independently represents hydrogen, C<SB>1</SB>-C<SB>12</SB> alkyl, aryl, substituted aryl or C<SB>4</SB>-C<SB>6</SB> cycloalkyl;<BR> each R<SP>2</SP> independently represents C<SB>1</SB>-C<SB>12</SB> alkyl, aryl, substituted aryl, C<SB>4</SB>-C<SB>6</SB> cycloalkyl or -(CH<SB>2</SB>)<SB>2</SB>NR<SP>3</SP><SB>2</SB> (where R<SP>3</SP> = C<SB>1</SB>-C<SB>12</SB> alkyl, aryl or substituted aryl, or R<SP>3</SP><SB>2</SB> = -[CH<SB>2</SB>]<SB>p</SB>-, where p = 4-6);<BR> n = 2, 3 or 4;<BR> R<SP>4</SP> represents a divalent, trivalent or tetravalent group being an aromatic group, a C<SB>2</SB>-C<SB>10</SB> aliphatic group, or a linear or branched polyalkyleneoxy group; and wherein compounds of formula (II) may also be attached to a surfactant molecule] are contrast and imaging agents. These lipophilic dyes can be used to differentiate between tissue groups, in the imaging and diagnosis of diseased lymph nodes) and in treatments involving the removal (by surgery) or in situ destruction of such matter (eg by photodynamic therapy, radiotherapy or sonodynamic therapy).

Description

METHOD AND COMPOUNDS FOR DEMARCATING TISSUE This invention relates to the use of certain dye compounds in diagnostic and surgical procedures, and in particular to the use of dye compounds to delineate tumor margins in surgery to remove tumors and in imaging and therapeutic techniques, e. g. photodynamic therapy (PDT).

It is often found that tumors are similar in colour and in texture to the healthy tissue in which they are embedded. Additionally, tumors often have irregular borders. However, since tumors are able to metastasize, the location, identification and subsequent removal of associated tumors and diseased lymph nodes is as important as the removal of the primary tumor.

Therefore, the ability to be able to clearly differentiate tumorous tissue from the surrounding benign tissue is important in that it will greatly facilitate the tumor's complete surgical excision, whilst at the same time minimising the amount of benign tissue removed. This latter factor is frequently an important factor in producing a successful surgical outcome and thus increasing the patient's quality of life and/or chances of long-term survival.

It has been found that a number of techniques including magnetic resonance imaging (MRI), ultrasound imaging and X-ray (e. g. CT) imaging can define both the location and approximate size of a tumor. However, all of these techniques are either not useful or unduly awkward for real-time guidance during actual surgery, and additionally are not as precise as direct visualisation.

The use of dyes in medicine has a long history. Their first uses were in attempts to kill microorganisms in water, staining tissues in the field of histology and later as diagnostic aids.

The importance of fluorescence has always been recognised, both for its enhanced visualisation properties and also for its association with disinfection. It was first reported by Policard et al. in Compt. Rend. Soc. Biol. 91 (1924) 1423 that both animal and human tumors could exhibit a red fluorescence, this being attributed to the accumulation of endogenous porphyrins. More recently Figge et al in Proc. Soc. Exp. Biol. Med. 68 (1948) 600, observed that certain porphyrin derivatives preferentially localized in tumors and thus considerable efforts have subsequently been directed towards the use of dyes, especially hematoporphyrin derivatives, as the agents of photodynamic therapy (PDT) for the treatment of tumors (see Kessel [Ed.], in"Photodynamic Therapy of Neoplastic Disease" (2 volumes), CRC Press (1990)). In this technique the aim is to selectively stain tumors with dyes and subsequently expose them to light. This results, with varying degrees of success, in the destruction of the tumor.

An alternative approach to tumor therapy is provided by recognising that the ability to selectively stain tumors with a dye would be a valuable aid in their subsequent surgical removal (see Moore in Science 106 (1947) 130, where fluorescein was used to aid in the location of gastric carcinomas). In addition to fluorescein, methylene blue was frequently used, often to stain the sometimes difficult to locate parathyroid glands (see Wheeler et al., in Amer. J. Surg. 143 (1982) 713).

Fluorescein continues to find use, for example see Googe et al. in Ophthalmology 100 (1993) 1167 wherein its use in angiography is described. On the other hand, haematoporphyrin derivative, a first generation PDT agent obtained from a chemical treatment of hematoporphyrin, has also been proposed for the diagnosis of cancer when used with infrared fluorescence detection (see Profio in IEEE J. Quant. Elect. QE-20 (1984) 1502).

Other classes of dye used include porphyrin derivatives, for example see Takemura et al. in Photochem. Photobiol.

59 (1994) 366, and indocyanine green (ICG), a cyanine dye, that has been used for human gliomas, for example see Haugland et al. in Neurosurgery 38 (1996) 308.

The following listed patents describe dyes previously disclosed in this field and are herein incorporated by reference: WO-A-96/17628, US-A-5672332, WO-A-97/18841, WO-A-96/23525, WO-A-95/20981 and WO-A-95/26754.

Optical imaging using contrast agents can be carried out with dyes which absorb in a wavelength range of 300 to 1300 nm. It has recently been found that the use of dyes both absorbing and fluorescing at wavelengths between 600 and 1300 nm is particularly advantageous, tissue penetration being greater at these wavelengths than with shorter or longer wavelengths. There is minimal absorption by bodily tissues at wavelengths in the range 600-900 nm.

In addition, it is possible to make use of modern inexpensive semiconductor diode laser dyes that emit in this wavelength region. Most importantly, these wavelengths are relatively harmless to the human body.

Dyes which fall into this category often have high extinction coefficients (e 2 105M-lcm-l), thus rendering tissues stained by them readily visible for traditional or laser surgery, consequently facilitating removal of the bulk of the tumor. The fluorescence of the dye can then be used to visualise any residual small tumor fragments which can then also be removed due to fluorescence being readily detected by the human eye.

Phthalocyanines are thus an especially advantageous class of dyes generally having high stability, low toxicity, absorption around 675 nm and strong fluorescence at a wavelength 5-10 nm higher. The absorption by the related naphthalocyanines is around 800 nm, also in the useful wavelength range, and the absorptions of mixed phthalo-/naphthalocyanines generally fall between 675 and 800 nm.

For example, Poon et al. in J. Neurosurg. 76 (1992) 679 details an intraoperative investigation using chloroaluminium phthalocyanine tetrasulfonate (ClAlPcS4) which fluoresces at 680 nm, for the delineation of rat gliomas. This compound, and other phthalocyanines, have been frequently investigated and shown to possess useful localising properties for PDT. However, their use has not yet achieved wide acceptance in practice.

It may be desirable to destroy residual stained tumor fragments by exposing the surgical site after removal of the tumor with an appropriate dose of light radiation at or near the absorption maximum of the dye. This process is known as post-surgical PDT. A number of recent studies have described the intraoperative use of PDT for cleaning up a tumor removal site after surgery, for example van Hillegersberg et al. in Drugs 48 (1994) 510.

To improve detection of the tumors, it is desirable for dyes to localise at the tumor site in an amount adequate for ready visualisation and that they are retained in adjoining healthy tissues to a significantly lower extent so that the two tissue types can readily be distinguished. Furthermore, the dyes should preferably possess high quantum yields of fluorescence in the presence of bodily fluids, thus enabling even small amounts of absorbed dyes to generate a readily visible fluorescence signal.

Laser surgery is particularly advantageous when used in conjunction with tumor localizing dyes, since the laser wavelength can be chosen to be close to the absorption wavelength of the dye, enabling stained tumorous tissues to be vaporized without significant damage to adjacent unstained normal tissues.

Dyes may be actively targeted to a tumor. Active targeting is defined as a modification of biodistribution using chemical groups that will associate with species present in the tumor tissue to effectively decrease the rate of loss of dye from the tumor tissue.

In such cases the dye is synthetically modified in order to facilitate its location at a specific tumor site.

Alternatively, dyes may passively distribute (i. e. passively target) into tumors which means that, even without the attachment of targeting vectors, they tend to accumulate in tumorous tissues.

Certain lipophilic materials have been found to localize in tumors effectively. For example, Fabris et al., J. Photochem. Photobiol. B : Biol. 39 279-284 (1997) reports that zinc octapentylphthalocyanine, incorporated in a Cremophor oil emulsion, was found to localize in MS-2 fibrosarcoma in 50-fold larger concentration than in peritumoral tissues. Faustino et al., Photochem.

Photobiol. 66 (4) 405-412 (1997). reports that a mesotetraphenylporphyrin derivative, incorporated in dipalmitoylphosphatidylcholine liposomes, was found to localize in tumor/peritumoral tissue at concentration ratios of from 100: 1 to 140: 1. These compounds were believed to be localized by a passive targeting mechanism based more on pharmacokinetics than on any specific biochemical interaction between the compound and the tissues at the targeting site. Recently, John et al, J. Med. Chem. 41 2445-2450 (1998) disclosed that certain lipophilic arylsulfonamides (not being dyes), especially those based on (2-aminoethyl)-pyrrolidine,piperidine, or-homopiperidine, actively interact with o-receptor binding sites, known to be expressed by a variety of human tumor cell lines, allowing high localizations in vivo and in vitro.

It has now been found that certain lipophilic dye compounds are capable of localizing particularly well in tumors and are therefore useful for imaging and therapy, including effectively delineating tumor margins or pinpointing tumorous tissue or cells, photodynamic therapy, radiotherapy or sonodynamic therapy.

Thus viewed from one aspect the invention provides a compound of formula (I)

M is a metal or metalloid; each

which may be the same or different, is an optionally substituted aromatic benzene or naphthalene nucleus; each R1, which may be the same or different, represents hydrogen, Cl-C12 alkyl, aryl, substituted aryl or C4-C6 cycloalkyl ; and each R', which may be the same or different, represents C1-Cl2 alkyl, aryl, substituted aryl, C4-C6 cycloalkyl or - (CH2) zNR32, where R3= alkyl (Cl-Cl2), aryl or substituted aryl, or R32 =-[CH2] p-, where p = 4-6.

By"optionally substituted aromatic benzene or naphthalene nucleus"above is meant that, in addition to being substituted by the group SO2NRlR2 shown in formula I above, each aromatic nucleus may additionally have one or more other substituent groups attached thereto. For synthetic reasons (see below), these substituent groups should in general be groups that activate the ring towards electrophilic reactions. Such groups are known to those skilled in the art and include-OH,-R (where R is alkyl, preferably Cl-Clo alkyl),-OR,-NX2 (where each X is H or R) and halogen.

The term"substituted aryl"above covers aryl substituted by one or more substituent group. In general, such groups should not be so hydrophilic in nature as to significantly impair the inherent lipophilicity of the compound of formula (I). Suitable substituent groups would include (but are not limited to) Cl-Clo alkyl, aryl, substituted aryl,-OR (where R is C1-Cl0 alkyl) and halogen. Other suitable groups will be apparent to a person skilled in the art.

The compound of formula (I) wherein M is zinc, each

is a benzene nucleus which is unsubstituted (other than by the-SO2NR1R2 groups shown in formula (I)) and all the groups Rl and R2 are n-octyl is known and is therefore excluded per se from the scope of the present invention.

Viewed from a further aspect the invention provides a compound of formula (II)

wherein M,

Rl and R2 are as defined above; n = 2,3 or 4, preferably 2 or 4; and R4 represents a divalent, trivalent or tetravalent group being an aromatic (e. g. arylene or substituted arylene) group, a C2-Clo aliphatic group, or a linear or branched polyalkyleneoxy group, e. g. a group derived from a polyethyleneoxide, a polypropyleneoxide or a copolymer of these, or a group derived from Pluronic or Tetronic surfactants (available from BASF). The said polyalkyleneoxy group should have a molecular weight in the range 100 to 50000, especially 1000 to 25000.

In the compounds of the invention M may be any metal or metalloid, e. g. Zn, Al, Co, Mg, Cd, Si, Ni, V, Pb, Cu or Fe. It is preferred that M is Zn, Al or Si.

In the compounds of the invention it is also preferred that R2 represents-(CH2) 2NR32 wherein R32 =-[CH2] p-, where p = 4-6. Such compounds are believed to be especially advantageous because they have a strong binding power for o-receptor sites in tumors, leading to enhanced tumor localization.

The compounds of the invention are sulfonamido substituted phthalocyanine dye compounds. For the purposes of the present application, it is to be understood that the term"phthalocyanines"is intended to include naphthalocyanines as well as mixed phthalo/naphthalocyanines. Likewise the term"phthalic" should be taken to include"naphthalic".

The compounds of the invention can be obtained from the corresponding sulfonic acids by treatment with phosphorus pentachloride or thionyl chloride in a suitable solvent (e. g. chlorosulfonic acid), to produce the sulfonyl chloride, followed by reaction with the amine R1R2NH, also in a suitable solvent such as DMF.

The sulfonic acid precursors can be made either by sulfonation of the corresponding phthalocyanine molecule, or by direct synthesis from sulfonated phthalic compounds (typically the acid or nitrile) by the process known as"tetramerization". In the former case, the preferred reagent for sulfonation is chlorosulfonic acid (prolonged reaction at reflux, approximately 150-160 C). Tetramerization is generally effected according to the method of Weber and Bush in Inorg. Chem. 4,469 (1982). This involves reacting a 4sulfophthalic acid derivative (e. g. the anhydride or the mono-ammonium salt) with urea and a salt of the metal (loid) in a suitable solvent. Another suitable starting material for the tetramerization reaction would be 4-sulfophthalic acid (which is commercially available) and the tetrasulfo-phthalocyanine product would then need to be converted to the sulfonyl chloride followed by isolation and hydrolysis to give an analytically pure material (see Griffiths et al., Dyes and Pigments 33 (1), 65-78 (1997)).

Compounds of formula (II) above can be prepared by initially reacting n molar equivalents of the aforementioned sulfonyl chloride with one equivalent of the di-, tri-or tetra-amino compound R4 (NH2) n followed by reaction with 3n equivalents of the monoamine R1R2NH.

Viewed from another aspect, the invention provides a method of treatment of the human or non-human animal (e. g. mammalian, avian or reptilian) body to remove diseased (e. g. tumorous) tissue therefrom, comprising the steps of: (a) administering to said body a compound of formula (I) or formula (II) and allowing it to accumulate at diseased tissues or cells therein; and (b) removing or destroying in situ the said diseased tissues or cells.

It should be appreciated that the method of treatment described above may be such that the distance to the surface of the said body where the compound accumulates is such that the compound may be visible at the surface of said body. In this manner the dye compound may be external to said body or, alternatively, internal to said body but exposed by surgery, etc.

Viewed from another aspect, the invention provides the use of a compound of formula (I) or formula (II) for the manufacture of a medicament for use in a method of treatment of the human or non-human animal body to remove diseased (e. g. tumorous) tissue or cells therefrom or to destroy diseased (e. g. tumorous) tissue or cells therein.

Viewed from a further aspect, the invention provides a method of imaging of the human or non-human animal (e. g. mammalian, avian or reptilian) body, comprising the steps of: (a) administering to said body a light imaging contrast agent being a compound of formula (I) or formula (II); (b) allowing said agent to accumulate at a part of said body suspected of containing or at risk of containing a tumorous lesion, tumor cells or a diseased lymph node; and (c) generating by a light imaging modality an image of at least said part of said body to which said agent distributes.

As used in this application,"light imaging"refers to diagnostic procedures that result in an image of the interior of the body or of the surface of the body by a process involving propagation through or reflection from the body of electromagnetic radiation with a wavelength in the range 300 to 1300 nm. The propagating electromagnetic radiation can result either from irradiation of the body or a portion of the body with light in the specified wavelength range or by generation of light within the wavelength range in the body or on the surface of the body by processes such as bioluminescence, sonoluminescence, or fluorescence.

The propagating light can be detected directly with sensors at the surface or within the body or indirectly after the generation from the light of another form of energy such as sound, ultrasound, heat, or electromagnetic radiation outside of the wavelength range 300 to 1300 nm. A sensor is a device that converts the detected light, sound, ultrasound, heat or other form of signal into a recordable form such as electrical current. An example of a light sensor is a photomultiplier tube. A sensor for light may also consist of a fiber-optic cable leading from the point of detection to a photomultiplier tube. In a simple embodiment of light imaging the sensor consists of the human eye.

Viewed from a yet further aspect, the invention provides the use of a compound of formula (I) or formula (II) for the manufacture of a medicament for use in a method of treatment or diagnosis which involves administering to a subject a contrast agent being a compound of formula (I) or formula (II) and generating by a light imaging modality an image of at least said part of said body suspected of containing or at risk of containing a tumorous lesion, tumor cells or a diseased lymph node.

Viewed from a still further aspect, the invention provides a pharmaceutical composition comprising a physiologically tolerable compound of formula (I) or formula (II) together with at least one physiologically tolerable carrier or excipient, e. g. a composition comprising such a compound in a sterile, pyrogen-free aqueous carrier medium.

Viewed from a yet still further aspect, the invention provides a compound of formula (I) or formula (II) for use in therapy or diagnosis.

Where the dye compound used according to the invention is administered in particulate form, this is preferably: (i) a nanoparticulate form having a mean particle size of up to 100 nm, e. g., 2 to 90 nm, preferably 8 to 80 nm; (ii) a liposomal form with the dye compound within the liposome core or associated with the liposomal membrane; (iii) a droplet form (i. e. an oil-in-water emulsion); or (iv) in a form satisfying two or more of the foregoing criteria. Nanoparticles, e. g. of a dye compound or containing or coated with a dye, are one possible format having ability to passively target tumor tissue and lymph nodes. For further details about particulate contrast agents, explicit reference is made to our International Patent Publication No. WO 96/23524, the entire contents of which are incorporated herein by reference.

Combinations of dye can be used in the methods of the present invention, wherein the dyes used can be the same or different chemical structures.

The dye compounds used according to the invention can either be used alone or in combination with other dyes.

In addition, it is possible to use combinations of different dye compounds according to the invention.

Suitable dye compounds for use in combination with this invention are disclosed in the copending patent application No. PCT/GB98/01245 of Nycomed Imaging AS, the entire contents of which are incorporated herein by reference.

In one aspect, a physiologically tolerable contrast agent of this invention comprises a compound of formula (II) attached to a surfactant molecule.

In this invention, a surfactant molecule is defined as an emulsifier or detergent as listed in McCutcheon's Directories, Volume 1: Emulsifiers and Detergents (1994), and which contains at least one chemical functional group selected from the group consisting of an alcohol (OH), a nitrilo group including a primary amine (NH2) and a secondary amine (NH), a carboxylic acid (COOH), a sulfhydryl (SH), a phosphoric acid group, phosphonic acid group, a phenolic group, a sulfonic acid group, a carbon-carbon double bond, and a ketone.

Chemical functional groups in the surfactant molecules can be interconverted by chemical reactions well known to those skilled in the art. For example, a hydroxyl group can be converted to a methanesulfonic acid ester which can be treated with sodium azide and reduced to form an amine group. Carboxylic acid groups and ketones can be reduced to form alcohols, and alcohols can be oxidized to form ketones, aldehydes, and carboxylic acid groups.

Useful surfactant molecules are emulsifiers or detergents which can function as dispersing agents, wetting agents, adsorbents, anticaking agents, soil antiredispositioning agents, antistats, binders, carriers, pearlescents, conditioning agents, hydrotropes, defoamers, emollients, flocculants, humectants, lubricants, opacifiers, plasticizers, preservatives, release agents, scale inhibitors, stabilizers, suspending agents, thickeners, W absorbers, water repellants, waxes, and polishes, and which contain at least one chemical functional group selected from the group consisting of an alcohol (OH), a nitrilo group including a primary amine (NH2) and a secondary amine (NH), a carboxylic acid (COOH), a sulfhydryl (SH), a phosphoric acid group, a phosphonic acid group, a phenolic group, a sulfonic acid group, a carbon-carbon double bond, and a ketone.

Preferably, the surfactant molecule comprises a polyalkyleneoxide moiety, optionally containing a branching group as defined herein; more preferably a polyalkyleneoxide block copolymeric moiety, optionally containing a branching group as defined herein; and most preferably a polyalkyleneoxide block copolymeric moiety optionally containing a branching group as defined herein and comprising a polypropylene oxide block and a polyethyleneoxide block. Examples of useful surfactant molecules include block copolymers such as AL 2070 available from ICI Surfactants, Antarox block copolymers available from Rhone-Poulenc, Delonic block copolymers available from DeForest, Inc., Hartopol block copolymers available from Texaco Chemical Canada, Macol block copolymers available from PPG Industries, Marlox block copolymers available from Huls America, Pluronic block copolymers including Pluronic F, L, P and R available from BASF Corp., Poly-Tergent block copolymers available from Olin Corp., and Tetronic and Tetronic R block copolymers available from BASF Corp. Currently preferred surfactant molecules include Tetronic and Pluronic block copolymers, and currently most preferred are Tetronic block copolymers.

Compounds of formula (II) can incorporate surfactant molecules. In one aspect, a chromophoric group can be chemically bound to a surfactant group by means of reaction with a chemical functional group on the surfactant molecule using chemical modifications well known to one skilled in the art. An example of such reactions include formation of sulfonamide linking groups by reaction with an amino group on a chemically modified surfactant molecule with a sulfonyl chloride (or other precursor) to a compound of formula (II).

That is to say, the R'bridging group in this case is derived from the desired surfactant.

Preferred contrast agents can be prepared from Pluronic and Tetronic block copolymer surfactant molecules and from linear and branched polyoxyethylene oxides, polyoxypropylene oxides, and copolymers of these, by first converting the hydroxyl functional groups to amine groups and then reacting the amine-containing surfactant molecules with a phthalocyanine sulfonyl chloride to yield, after further reaction with an amine R1R2NH, compounds of formula (II).

Attachment of compounds of formula (II) to a surfactant molecule can occur at the ends of the polymer backbone, at the ends of the branching groups, or both.

In cases where either the surfactant molecule or the attached compound of formula (II) are ionically charged, a counterion may be associated to provide charge neutrality. Meglumine is particularly useful for incorporation as a counterion, although other counterions of appropriate charge might also be employed.

Examples of preferred contrast agents include the following wherein R is a methyl group.

R Chromophore- (CH2cRp).- (CH2m),- (Ct-hc4l2O).-Chromophore R R Chromophore- (CH2C-HO- (CH2CH20),- (CH2CHO),-Chromophore R R Chromophore- (CHCH : 0),- (CHcno) y (CHCHO) y- (CHCH : 0),-Chromophore R R Chromophore- (CH : CH, 0),- (CH : cwo) y (CH, CHo- (CHt < 0),-Chromophore Chromophore- (CHHO) y- (CH : CHO), (CHCH)),- (CH/o-Chromophore R N CH2CH2-N R Chromophore- (CHtCHO),- (CHH20)/ (CH : CHO),- (CH/ > -Chromophore Preferably, the surfactant molecule T-908 (BASF Corporation) can be modified by converting the terminal OH groups to provide an amine group on each branch of the block copolymeric T-908. The modified polymer can then be reacted with a compound of formula (II).

The dye compounds used according to the invention may be administered by any convenient route, for example by injection or infusion into muscle, tumor tissue, or the vasculature, subcutaneously, or interstitially, by administration into an externally voiding body cavity (e. g. into the digestive tract (for example orally or rectally), vagina, uterus, bladder, ears, nose or lungs), by transdermal administration (e. g., by iontophoresis or by topical application), or by topical application to a surgically exposed site.

In general, parenteral administration, e. g., of a solution or dispersion of or containing the dye compound, will be preferred.

The administration forms used may be any of the forms conventionally used for administration of pharmaceuticals, e. g., solutions, suspensions, dispersions, syrups, powders, tablets, capsules, sprays, creams, gels, etc.

The dye compound may be presented in particulate form, e. g. liquid droplets of or containing the dye (e. g. in solution in a water-immiscible fluid), or solid or semisolid particles of, containing or coated with the dye.

This latter category includes vesicles (e. g. liposomes, micelles or microballoons) containing the dye compound.

Particles are one possible presentation form for the dye. These have an intrinsic light scattering effect.

Particle sizes may range from a few nanometers to about 20 micrometers, e. g. 10 to 20 000 nm. However, the larger particle sizes (above 10 micrometers) will generally be used only with deformable particles.

Where the particles contain other components besides the dye compound, e. g. matrix or membrane forming materials, coating agents, contrast agents, solvents, gases or gas generators, etc. these will conveniently be materials which are physiologically tolerable at the dosages used.

The formation of droplets, coated particles, composite particles, vesicles, etc. is well described in the literature, especially that relating to pharmaceutical and contrast agent (e. g. ultrasound contrast agent) preparation and formulation.

It may be preferred to inject the dyes of the present invention directly into the tumor. Thus it is possible to directly inject dyes of the present invention or suspensions of insoluble dyes of the present invention in order to stain tumors before surgical resection. The dyes will mark the tumor to the margins for an extended period of time such that surgical resection is facilitated or for PDT.

Such particulate suspensions of the dye afford an advantage over conventional dye solutions in terms of residence times within the tumor. A further advantage over conventional intravenous administration of the dyes is that the direct injection technique removes the need for a vector to status of controlled drug delivery system-overview", Naik, S. R.; Shanbhag, V., Indian Drugs, 30, Sep 1993, 423-429;"Novel formulation strategies for improving "oral"bioavailability of drugs with poor membrane permeation or presystemic metabolism", Aungst, B. J., Journal of Pharmaceutical Sciences (USA), 82, Oct 1993, 979-987; Remington's Pharmaceutical Sciences, A. Osol, ed., Mack Publishing Co. 1975, Part 6, chp 40 and references therein. (pp. 731-753), Part 8, all chps (pp.

1355-1644); The Extra Pharmacopoeia, Martindale, 29th Edition, The Pharmaceutical Press, London, 1989.

Administration of drugs and other agents by this route is often preferred due to enhanced patient compliance (for repeated dosing) and ease of administration. It is well known in the art that not every agent is bioavailable via this route; that is to say that not all molecules are 1) chemically stable in the environs of the gut, 2) transportable across alimentary membranes for absorption into the blood/lymphatics, and 3) active even if accessible due to metabolic processes within the gut or possible solubility issues, etc.

Additional methods of administration include the following: air guns, inhalation, aerosols, body cavity washing (i. e. enemas), and tissue marking devices (i. e. pens and tattoo needles).

It is also known that the addition of penetration enhancers such as some fatty acids, some bile salts, and other lipophilic compounds can enhance the bioavailability of the drug/dye of interest. Further, the use of cyclodextrins may alter the penetration and bioavailability of normally non-available dyes by the oral route. Formulating the dye of interest in a polymeric composition which effectively"coats"the lining of the gut will also enhance the availability of the dye by artificially increasing the concentration of the dye at the lining of the gut.

All of the known routes of administration of drugs/agents to mammals are envisaged according to the present invention.

While the dye compounds of the invention are particularly suited to intraoperative and post-surgical PDT use to facilitate visualization of tumor margins and optimize the surgical removal and PDT destruction of tumor tissues and cells, they can also be used as contrast agents in light imaging of tumor tissue, tumor cells and diseased lymph nodes. In addition, the dye compounds of the invention are suited to the following medical uses: removal of arterial plaque, burn treatment, cauterization, cryosurgery/hyperthermia (dye guidance of the administration of cold/heat), treatment of dental/gum diseases, dermabrasion (use of a wire brush, for example, to remove cells), directing the application of chemotherapeutic agents, measurement of dynamic flow or tissue perfusion, electrolysis, electrophoresis, application of embolic agents, detection and treatment of endometriosis, tissue implantation (dyes contained in implants can be used to monitor the integrity of the implant), fluid marker (dyes can be added to bodily fluids to monitor the flow, location, swelling etc.), focused ultrasound therapy (dyes guide the placement of the ultrasound transducer), marking sites of inflammation and infection, lavage therapy, lymph node detection, microwave therapy, MRI in real time (this having neurosurgical applications) when the central metal M is gadolinium or other suitable paramagnetic metal atom, marking nerve bundles, marking neural tumors, oncology procedures (such as tumor marking and lymph node involvement), detection of pathological conditions (i. e. tumors, lumps, cysts (both benign and malignant)), peripheral metastases localization, photodynamic therapy, plastic and cosmetic surgery, radiation therapy (dyes can guide the placement of radiation equipment), sonodynamic therapy, surgical plane marking (dyes mark boundaries between tissue groups to allow surgeons to cut between instead of through a tissue group), tissue marking and tissue marking pens (dyes can be used in devices which draw or mark sections of tissue), tumor marking (dyes mark tumor sites using either passive or active targeting), vascular leaks (dyes can be used to determine the vascular integrity after the repair of vascular damage such as haematomas), vasectomies and tubal ligations (the dyes can be used to determine the integrity of any repairs) and for white blood cell markers.

One way to use dyes intraoperatively is in the visualization of dynamic flow or tissue perfusion. In this method, the tissue (generally a tumor) is exposed and the dye is then administered intravenously.

Depending on dye pharmacokinetics, the agent will generally begin in the blood pool, leak into the tumor, and then gradually fade as the dye is excreted or leaks into the surrounding tissue. Dynamic agents could help doctors discriminate between the necrotic core and actively growing tumor regions.

Dyes attached to capillary embolic agents can be used for light imaging purposes. Capillary embolic agents are a novel class of embolic agents which embolize the entire capillary bed of tumors or tissue malformations rather than simply blocking the feeding artery to those tissues or tumors. The dye or fluorescent agent can then be treated as a separate"drug"and delivered to the tumor by the X-ray, MRI, or ultrasound dense particles and trapped at the tumor site after embolus formation. In this manner, the tumor or lesion can be "marked"for ease of resection without the removal of normal tissue.

While both normal and pathological tissue can be marked to aid in removal, in reconstructive surgery tissue is not necessarily removed. Rather, boundaries are marked in order to aid in the repair. Plastic surgery is therefore another use for dyes of this invention and is defined herein as the restoration, reconstruction, correction, or improvement in the shape and appearance of body structures that are defective, damaged or misshapen by injury, disease, growth and development, aging, previous surgeries and environmental stresses.

By way of example, tissue repair would include treating burns victims and repairing congenital defects. Plastic surgery also includes the subdivision of cosmetic surgery, which is defined herein as procedures designed to improve the patient's appearance by plastic restoration, correction, removal of blemishes, etc.

A further use for dyes of this invention is in regard to surgical planes. Surgeons would like to have dyes which mark the margins of surgical planes. When operating, surgeons try to pass between tissue groups rather than through them but in some cases it is not always easy to see where the edge of one tissue group ends and another begins. Thus a dye that would enhance this demarcation would be particularly useful. By way of example, a dye whose distribution is controllable could be injected locally (i. e. subcutaneously or iontophoretically) in the area that the surgeon requires demarcated.

Diffusion could be controlled iontophoretically so that when the time came for surgery, the dye would be diffused along the surgical plane, thus allowing the surgeon to visualize the appropriate areas.

Alternatively, dyes with different hues (such as dyes containing different metals) could be individually sprayed or injected onto a surgical plane. Once the surgeon reached non-dyed tissue (such as tissue in another plane) a dye with a different hue would be spritzed or injected into the new area.

There are also times when the surgeon will have to remove normal tissue. Both pathological and healthy normal tissue can be marked with a dye in order to remove tissue. One example is liposuction. The fatty tissue to be removed in such a procedure does not have to have pathological conditions associated with it. A problem with the liposuction procedure is that often non-fatty tissue is also removed. A dye of the present invention could be used to stain either the fat or the non-fatty tissue offering visual clues to the surgeon as to when the suction step was leaving the fatty tissue behind. A further example is the removal of hair using electrophoretic techniques.

Furthermore, in addition to the above, it is often desired to remove tissue that is neither cancerous nor "normal". By way of example, a pituitary gland might be over-producing hormones which interfere with the normal development of the body and hence need to be removed.

Dyes of the present invention would help differentiate such non-,, normal", non-cancerous tissue groups.

A further use for the dyes of the present invention concerns their use in conjunction with another imaging or therapeutic agent. Such combinations will have the advantage of reducing the imaging and site-marking process to a single step, the dye being incorporated into the"standard", i. e. stand-alone, imaging or therapeutic agent. Therefore the dye need not be injected after the imaging or therapeutic agent is injected. One possible use for such imaging agent/dye combinations is in the determination of the spread of melanoma cancer. Traditionally, in order to determine the spread of such, a radioactive probe is injected into the lymph system associated with the melanoma and this is followed by an injection of dyes into the lymph nodes. Using imaging agent/dye combinations as described above, the dye and the radioactive probe will be combined together, thus reducing the procedure to a one-step process.

Furthermore, it is possible to use dyes of the present invention in contrast agents capable of generating multiple reporting signals (the signal being reported by means of radiation (in MRI, for example), ultrasound or light (where a change in refractive index, phase, frequency, amplitude, intensity, polarisation, and the like can be monitored)).

Many existing patents disclose the use of a given chelator agent which can be used in e. g. MRI (with Gd) or light (with Eu) studies). However, dyes of the present invention can be used synergistically in multiple modalities. By way of example, an agent can be used in one mode, e. g. as an MRI agent before surgery (i. e. in a non-invasive mode) to confirm the existence of a diseased state/structure. Then, during the actual surgical intervention, another mode (built into the contrast agent) would be used to guide the surgery, such as localize the tissue visually, demarcate tissue boundaries, differential staining of tissue (e. g. surgical planes) and/or use of different wavelengths to highlight functional biological aspects. Such contrast agents can be coupled to vectors such as proteins, peptides, DNA, polymers and the like.

The light imaging technique may involve recording a photographic image of a tissue or organ surface illuminated with a light source that causes the contrast agent to exert a contrast enhancing effect and make the unhealthy tissue stand out more clearly from the surrounding healthy tissue, e. g. due to characteristic light absorption or fluorescence by the contrast agent.

Such a photographic image may be recorded of an exposed surface (e. g. exposed during surgery) or may be recorded by insertion of an endoscope into a body cavity through a body orifice or through a surgical incision.

Alternatively, images may be recorded of light (generally laser light, especially at near infrared wavelengths) reflecting from or transmitting through body tissue. In these techniques, the use of a contrast agent facilitates detection and location of subsurface structures, e. g. tumors.

Other light imaging techniques may be used to record contrast enhanced images of shallow subsurface structures, e. g. within a millimeter of the surface.

Confocal scanning laser microscopy (CSLM) selectively images a single point within a test object by focusing light from a pinhole source onto that point. The light transmitting past or reflecting from that point is then refocused onto a second pinhole that filters out spurious light. Thus the detector behind the pinhole picks up the image of the point alone. Raster scanning of the point through a complete plane passing through the sample with the help of movable mirrors generates the image of a complete plane of points. Thus, CSLM is a means for"optically"sectioning a test sample.

Optical coherence tomography (OCT) accomplishes optical sectioning in a related but somewhat different manner.

A collimated beam of light is reflected from the sample, then is compared with a reference beam that has traveled a precisely known distance. Only the light that has traveled exactly the same distance to the sample and back as has the reference beam from the source to the detector constructively interferes with the reference beam and is detected. Thus, the light from a single plane within the sample is again selected.

CSLM and OCT are particularly suitable for examination of excised tissue. However, they could also be used for in vivo optical biopsy of suspicious skin lesions and for characterization of body surfaces that can be exposed endoscopically or surgically.

It is anticipated that CSLM and OCT will be especially useful in optically guided tumor resection. For example, either device attached to a colonoscope will facilitate determination of the appropriate depth to which a malignant colon polyp should be excised to ensure complete removal of cancerous tissue. Additional applications include, but are not limited to, diagnosis and treatment of disease conditions of the rest of the digestive tract, surgical treatment of ulcerative colitis, and diagnosis and treatment of endometriosis.

When either CSLM or OCT is used as a dermatological tool, scattering from melanosomes in the skin is believed to be responsible for producing contrast. The primary effect of these sites is to scatter or reflect light hitting them. Synthetic contrast agents can act either as scattering or absorbing agents.

A preferred contrast agent for intraoperative CSLM or OCT will have the following properties: It will consist of stabilized particles in aqueous or buffered solution.

The particle size will be around 200 to 1300 nm (roughly equal to the wavelength of the light source). The refractive index of the particles will differ from that of body fluids such as blood and lymph by at least 0.01.

The particles may be made of a dye compound or may contain or be coated with a dye compound, e. g. the particles may comprise a matrix material (e. g. a physiologically tolerable synthetic or non-synthetic polymer, such as an acrylate or polysaccharide) incorporating a dye compound, a core of a dye compound coated with a coating agent or encapsulated by a membrane forming material, or a core of a matrix material with a dye compound coated on or attached to the particle surface. The particles may be solid, semisolid or liquid and may be layered structures such as vesicles (e. g., micelles, liposomes and microballoons).

The dye compound used will preferably be a fluorescent material, particularly a material having an emission maximum in the near infrared range, especially in the range 650 to 1300nm. The dye compounds of formulae (I) and (II) above are thus suitable matrials. Optionally the particles may have suitable surface modifying agents, such as poly (ethylene glycol) to slow their uptake by macrophages in the body. Examples of suitable particulate agents are described in WO 96/23524.

Additional imaging methods which can be used with the dye compounds of the present invention include' photoacoustic (optoacoustic) imaging, acoustooptic imaging, two-photon and multiphoton fluorescence microscopy, endoscopy (bronchoscopy, colonoscopy, laparoscopy), fluorescence spectroscopy, frameless stereotaxy, intraluminial photothermoforming (see US-A5662712), intraoperative angiography, intraoperative Doppler, methods utilising polarized light or UV lamps, methods utilizing vision augmentation devices (e. g., night vision goggles, cameras, filters, computer imaging enhancement, virtual imaging devices, magnifying devices, prisms and polarizers) and scintigraphy.

The"photoacoustic"or"optoacoustic"effect is described by Tam in Reviews of Modern Physics, 58 (2), 381-431 (1986), and its application to medical imaging is described in our copending International Patent Application No. PCT/GB98/01751, the entire contents of which are incorporated herein by reference. Briefly, imaging may be effected by administering to the body of a patient a physiologically tolerable contrast agent comprising a radiation absorbing component and/or a pressure inducing component, exposing said body to radiation, detecting pressure waves generated in said body by said radiation and generating an optoacoustic image therefrom of at least a part of said body.

Acousto-optical imaging is a modified approach to light imaging in which focussed ultrasound is used to isolate optical signals from the body. Several mechanisms of interaction are possible. In one of these, the acoustic wave sets up moving regions of different pressure, density and refractive index that interact with the light in much the same way as a diffusion grating. The movement of the sound waves moreover induces a Doppler shift of the sound frequency into the light frequency making it possible to identify that portion of the light that has actually interacted with the sound wave. Thus the light that has passed through the focused ultrasound region may be separated from other components of the detected light because it is shifted in frequency and wavelength. Acousto-optic imaging is described for example in US-A-5171298, and by Wang et al, Optics Letters 20,629-631 (1995), Wang et al, Proc. Opt. Soc.

Amer. ATuB3-1, 166-168 (1996), Brooksby et al, Proc.

Soc. Photo-Opt. Instr. Engin. 2389,564-570 (1995), and in our co-pending International Patent Application No.

PCT/GB98/01438, the entire contents of which are incorporated herein by reference.

Contrast agents can be injected into the vasculature prior to or during surgery. For detection of lymph nodes they can be injected into a lymph duct draining into the surgical area. Alternatively, they may be applied during surgery as a topical ointment, a liquid, or a spray.

For dermatological applications, the contrast agents described in WO 96/23524 may be modified to be delivered through transdermal patches or by iontophoresis.

Iontophoretic delivery is preferred, as one can control the amount of the agent that is delivered.

The perfusion of tissue that is exposed by surgery is one important indicator of the health of that tissue.

One of the indicators of the degree of perfusion is the rate of blood flow within the tissue. Blood flow in the skin can be detected by laser Doppler blood-flow measurement or laser speckle interferometry, either by itself or in conjunction with CSLM or OCT.

Laser Doppler and speckle interferometry are related, and each relies upon the fact that the intensity of light detected after a beam of laser light that interacts with a collection of moving particles changes with time (Ruth, B.,"Blood Flow Determination by the Laser Speckle Method,"Int. J. Microcirc. : Clin.

Exp., 1990,9,21-45). Mathematical analysis of the changes provides a basis for calculating the rate at which the particles are moving.

When laser light with a wavelength between 300 and 1300 nm is reflected from the skin, the changing pattern of light reflecting back to a light detector results largely from movement of blood cells within the dermis.

However, speckle interferometry is best suited for determination of blood flow in vessels with diameters between 0.08 and 1 mm. Laser Doppler measurement is best used for blood vessels 0.08 mm or less in diameter (Ul'Yanov, S. S.; Tuchin; Bednow; Brill, G. E.; Zakharova, E. I.,"The Application of Speckle Interferometry for the Monitoring of Blood and Lymph Flow in Microvessels", Lasers in Medical Science, 1996,11,97-107). Light reflected from larger vessels, which lie deep within the dermis and in the underlying tissue, only serves to complicate the analysis of the light from the smaller vessels lying about 0.5 mm beneath the surface of the skin (Abbot, N. C.; Ferrell, W. R.; Lockhart, J. C.; Lowe, J. G.,"Laser Doppler Perfusion Imaging of Skin Blood Flow Using Red and Near-Infrared Sources", J.

Invest. Dermatol., 1996,107,882-886).

When the vasculature contains an absorbing dye, Beer's law shows that light passing through larger blood vessels will be more strongly attenuated than is light passing through smaller vessels. Furthermore, light scattering from blood cells in vessels deep within the skin and underlying tissue will be more attenuated than will light scattering from blood cells in vessels near the surface of the skin. Thus, the presence in the blood of a contrast agent with an absorption maximum near the wavelength of the laser light used for either Doppler or speckle interferometric measurements of blood flow improves the selectivity of the measurement for smaller vessels near the skin surface. An agent of the type taught by this invention is suitable and there must be a stable concentration of the agent in the blood over the course of the measurement.

The dyes of the invention may be administered to patients for imaging in amounts sufficient to be visualizable or to be effective in PDT in the particular surgical technique.

The dosage of the dye compounds of the invention will depend upon the condition being treated, but in general will be of the order of from 1 pmol/kg to 1 mmol/kg bodyweight.

The dye compounds of the present invention may be formulated with conventional pharmaceutical or veterinary aids, for example emulsifiers, fatty acid esters, gelling agents, stabilizers, antioxidants, osmolality adjusting agents, buffers, pH adjusting agents, etc., and may be in a form suitable for parenteral or enteral administration, for example injection or infusion or administration directly into a body cavity having an external escape duct, for example the gastrointestinal tract, the bladder or the uterus.

Thus, the compounds of the present invention may be in conventional pharmaceutical administration forms such as tablets, capsules, powders, solutions, suspensions, dispersions, syrups, suppositories, etc. However, solutions, suspensions and dispersions in physiologically acceptable carrier will generally be preferred.

The dye compounds according to the invention may therefore be formulated for administration using physiologically acceptable carriers or excipients in a manner fully within the skill of the art. For example, the compounds, optionally with the addition of pharmaceutically acceptable excipients, may be suspended in an aqueous medium, with the resulting suspension then being sterilized.

For some portions of the body, the most preferred mode for administering the dye compounds is parenteral, e. g. intravenous administration. Parenterally administrable forms, e. g. intravenous dispersions, should be sterile and free from physiologically unacceptable agents, and should have low osmolality to minimize irritation or other adverse effects upon administration, and thus the contrast medium should preferably be isotonic or slightly hypertonic. Suitable vehicles include aqueous vehicles customarily used for administering parenteral solutions or dispersions such as Sodium Chloride Injection, Ringer's Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, Lactated Ringer's Injection and other solutions such as are described in Remington's Pharmaceutical Sciences, 15th edn., Easton: Mack Publishing Co., pp. 1405-1412 and 1461-1487 (1975) and The National Formulary XIV, 14th edn. Washington: American Pharmaceutical Association (1975). The solutions or dispersions can contain preservatives, antimicrobial agents, buffers and antioxidants conventionally used for parenteral solutions, excipients and other additives which are compatible with the dyes and which will not interfere with manufacture, storage or use.

All of the publications referred to herein are incorporated herein by reference.

The invention will now be described further with reference to the following non-limiting Examples.

Example 1 Preparation of a compound of formula (I) wherein M = Zn R'= H and R=- ~ (CH212N (CH2) 5.

Zinc phthalocyanine tetrasulfonyl chloride (0.97 g, 1.0 mM), 1- (2-aminoethyl) piperidine (0. 51 g, 4.0 mM), DMAP (0.01 g, 0.08 mM), dichloromethane (2 5ml), and saturated NaHCO3 solution (25 ml), were stirred under nitrogen for 24 hours. The dichloromethane solution was extracted with water, dried and evaporated to yield a dark blue solid, Amax 674 nm (methanol), 678 nm (dichloromethane).

Example 2 Preparation of a compound of formula (II) wherein M=Al.R=R=CH (n-decyi). n = 2 and R4 = phenylene 1,4-Phenylenediamine hydrochloride (0.18 g, 1.0 mM), chloroaluminumphthalocyanine tetrasulfonyl chloride (1.94 g, 2.0 mM), 4- (dimethylamino) pyridine (DMAP, 20 mg, 0.16 mM), pyridine (5.0 ml, 62 mM), and dichloromethane (50 ml) were mixed and stirred under nitrogen for 3 days. Decylamine (1.3 ml, 6.5 mM) was added, and the mixture stirred for a further 2 days.

The reaction mixture was filtered, and the solid product washed with dichloro-methane and water, and dried in a vacuum oven to yield a dark blue solid, 1.6 g, lambda max. 678 nm (methanol).

Claims (14)

1. CLAIMS: 1. A compound of formula (I)

   wherein M is a metal or metalloid; each

   which may be the same or different, is an optionally substituted aromatic benzene or naphthalene nucleus; each R1, which may be the same or different, represents hydrogen, Cl-Cl2 alkyl, aryl, substituted aryl or Cl-C6 cycloalkyl ; and each R', which may be the same or different, represents Cl-Cl2 alkyl, aryl, substituted aryl, C4-C6 cycloalkyl or - (CH2) 2NR32, where R3 = alkyl (Cl-Cl2), aryl or substituted aryl, or R32 =-[CH2] p-, where p = 4-6; but excluding the compound wherein M is zinc, each

   is an otherwise unsubstituted benzene nucleus and all the groups Rl and R2 are n-octyl.
2. 2. A compound of formula (II)

   wherein M,

   R1 and R2 are as defined in claim 1, n = 2,3 or 4; and R4 represents a divalent, trivalent or tetravalent group being an aromatic group, a C2-Clo aliphatic group, or a linear or branched polyalkyleneoxy group.
3. 3. A compound as claimed in claim 1 or claim 2 wherein M represents Zn, Al, Co, Mg, Cd, Si, Ni, V, Pb, Cu or Fe.
4. 4. A compound as claimed in claim 1 or claim 2 wherein M represents Zn, Al or Si.
5. 5. A compound as claimed in claim 1 or claim 2 wherein R2 represents-(CH2) 2NR32 wherein R32 =-[CH2] p-, where p = 4-6.
6. 6. A process for preparing a compound of formula (I) as claimed in claim 1, comprising the steps of: (a) treating a compound of formula (III)

   (wherein M and

   are as defined in claim 1) with an amine of formula R1R2NH (wherein R'and R'are as defined in claim 1) in a suitable solvent.
7. 7. A process for preparing a compound of formula (II) as claimed in claim 2, comprising the steps of: (a) treating a compound of formula (IV)

   (wherein M and

   are as defined in claim 1, and n and R are as defined in claim 2) with an amine of formula R'R 2NH (wherein Rl and R2 are as defined in claim 1) in a suitable solvent.
8. 8. A method of treatment of the human or non-human animal body to remove diseased tissue therefrom, comprising the steps of: (a) administering to said body a compound of formula (I) or formula (II)

   (wherein M is a metal or metalloid; each

   which may be the same or different, is an optionally substituted aromatic benzene or naphthalene nucleus; each Rl, which may be the same or different, represents hydrogen, Cl-Cl2 alkyl, aryl, substituted aryl or C4-C6 cycloalkyl ; each R2, which may be the same or different, represents C,-Cl2 alkyl, aryl, substituted aryl, C4-C6 cycloalkyl or - (CH2) 2NR32, where R3 = alkyl (Cl-Cl2), aryl and substituted aryl, or R32 =-[CH2] p-, where p = 4-6 ; n = 2,3 or 4; and R4 represents a divalent, trivalent or tetravalent group being an aromatic group, a C2-Clo aliphatic group, or a linear or branched polyalkyleneoxy group) and allowing it to accumulate at diseased tissues or cells therein; and (b) removing or destroying in situ the said diseased tissues or cells.
9. 9. The use of a compound of formula (I) or formula (II) as defined in claim 8 for the manufacture of a medicament for use in a method of treatment of the human or non-human animal body to remove diseased tissue or cells therefrom or to destroy diseased tissue or cells therein.
10. 10. A method of imaging of the human or non-human animal body, comprising the steps of: (a) administering to said body a light imaging contrast agent being a compound of formula (I) or formula (II) as defined in claim 8; (b) allowing said agent to accumulate at a part of said body suspected of containing or at risk of containing a tumorous lesion, tumor cells or a diseased lymph node; and (c) generating by a light imaging modality an image of at least said part of said body to which said agent distributes.
11. 11. The use of a compound of formula (I) or formula (II) as defined in claim 8 for the manufacture of a medicament for use in a method of treatment or diagnosis which involves administering to a subject a contrast agent being a compound of formula (I) or formula (II) as defined in claim 8 and generating by a light imaging modality an image of at least said part of said body suspected of containing or at risk of containing a tumorous lesion, tumor cells or a diseased lymph node.
12. 12. A pharmaceutical composition comprising a physiologically tolerable compound of formula (I) or formula (II) as defined in claim 8 together with at least one physiologically tolerable carrier or excipient.
13. 13. A compound of formula (I) or formula (II) as defined in claim 8 for use in therapy or diagnosis.
14. 14. A contrast agent comprising a compound of formula (II) as defined in claim 2 attached to a surfactant molecule.