WO2023137605A1

WO2023137605A1 - Medical grade silicone gel pad with pressure technology for treatment of hypertrophic scars

Info

Publication number: WO2023137605A1
Application number: PCT/CN2022/072645
Authority: WO
Inventors: Wai Ping Cecilia TSANG
Original assignee: Hercz Rehabilitation Technology Limited
Priority date: 2022-01-19
Filing date: 2022-01-19
Publication date: 2023-07-27

Abstract

A medical grade silicone gel sheet designed with pressure technology for treatment of post surgery hypertrophic scars. The silicone gel sheet is consisted of a silicone gel layer (1), a silicone rubber fixing layer (2,3) with the designs of silicone rubber columns with different height and a silicone based pressure band (4). This silicone gel sheet can provide the optimal pressure for pressure management as well as the property of silicone gel to moisture the hypertrophic scars. It can evenly apply pressure to the concave and convex parts of the body contour to ensure the effectiveness of scar treatment and long-term wearing comfort.

Description

MEDICAL GRADE SILICONE GEL PAD WITH PRESSURE TECHNOLOGY FOR TREATMENT OF HYPERTROPHIC SCARS

FIELD OF THE INVENTION

The invention belongs to the technical field of bandages or dressings. Specifically, the present invention relates to a medical grade silicone gel pad with pressure technology for treatment of hypertrophic scars.

BACKGROUND OF THE INVENTION

Burn injuries are caused by fire, chemicals, electricity, and friction and can vary in severity. First degree burns are the least severe, causing redness, and healing relatively quickly. On the other end of the spectrum, fourth degree burns are the most severe, burning down to the level of the muscle and bone. Second and third degree burns fall between these extremes. Both burn and skim injuries caused in formation of hypertrophic scar. As this have higher incidence of hypertrophic scar. Hypertrophic scar is characterized by its hard, raised, dark pigmentation cause skin contracture and sometimes need debridement. It is well known that silicone compounds and, particularly, silicone gels are effective in reducing thickness, redness and hardness of scar tissue resulting from burns, surgeries, or other skin trauma, and to some extent, for improving the condition of scar tissue. Although the pathogeneses for such treatment may not be fully understood, the results have been recognized and substantiated. Moreover, there are a number of prior references which support the use of silicone containing compounds and, particularly, silicone gels for treating the hypertrophic scar .

The International Society for Burn Injuries (ISBI) has documented that the application of pressure therapy and silicone therapy as the first-line conservative treatment for hypertrophic scar in the practice guidelines for Burn Care in 2016. Since the 1970s, Larson and others have discovered that compression therapy can reduce the thickness of hypertrophic scars, and compression therapy has gradually been promoted in burn or scar treatment centers worldwide. Currently, bandages, customized pressure garments or pressure pads are mainly used clinically to manage hypertrophic scars. Through a systematic evaluation and analysis, it was shown that pressure therapy can effectively reduce the thickness of hypertrophic scars (Anzarut A, 2009) . Van Den Kerchohove 2005 also found in a randomized controlled trial that the pressure of 15 mmHg was more effective in reducing scar thickness than the pressure group of 10 mmHg. Similar effects of high pressure group 20-25 mmHg was more effective than the 10-15 mmHg group were also found in the randomized controlled trial of Candy Lai et al. in 2010. A most recent systematic review showed that pressure therapy ranged between 20mmHg to 30mmHg was found to be most effective (Patricia A Sharp et al 2016) .

In the past, the application of pressure was usually prescribed using tailored made pressure garments, elastic bandage, or elastic tapping.

The mechanism of how silicone exerts its effect on hypertrophic scar is believed to be related to hydration and moisturization of the scar tissue. It was found that the application of silicone gel pad will release small silicone oil molecules on the tissue, thus reducing water loss from the scar tissue and enhance the moisturization of the scars. With the sufficient hydration, the tension of the scar tissues will be reduced. There will be a decrease of production of collagen fibers on the scars, thus minimized the production of hypertrophic scar. In 1987, Quinn conducted a study on 92 patients with hypertrophic scars and keloids and found that 81.5%of the patients had improved scars after using silicone treatment.

SUMMARY OF THE INVENTION

In view of above, this invention is designed based on the concepts of combined pressure and silicone intervention to develop a product which could achieve both pressure and silicone effect to manage surgical scars. Based on previous studies, the prevalence rate of hypertrophic scar formation could range from 30-60 %. The theories built up using combined therapy are adopted to manage surgical scars which are characterized by its longitudinal and narrow appearance.

In order to accomplish the objective of the present disclosure, the following technical solutions are proposed.

The invention is designed with a pressure pad, which is a sheet of medical silicone gel sheet covered with another rubber sheet designed with multiple protruding studs with different height on top. A silicone elastic pressure band is the applied on the top of this stud pad. The protruding cylindrical rubber studs will help to generate evenly pressure on the scar. The longitudinal design of the pressure pad is specially developed for the management of the surgical scar which is typically longitudinal and narrow. It is also meant to cater for concave and convex body surface of human body eg limbs, chest. The whole package of combined pressure pad and silicone elastic pressure band.

Specifically, the present invention provides a pressure pad, which is a silicone gel sheet is designed with a silicone gel bottom layer (1) , a silicone rubber fixing layer (2, 3) and a silicone elastic pressure band (4) .

In some embodiments, the pressure band (4) is a Polyurethane (PU) elastic fabric band coated with a medical grade silicone gel layer.

In some embodiments, the pressure band (4) has a thickness of less than 0.5 mm and an adhesion of 40-80 N/m.

In some embodiments, the pressure band (4) is longer and wider than the silicone rubber fixing layer.

In other embodiments, the silicone gel bottom layer (1) has a thickness of 2 mm, a hardness of 0-1 Shore A Hardness and an adhesion of 10-20 N/m.

In other embodiments, the silicone rubber fixing layer comprises a middle layer (2) and a protruding layer (3) .

In other embodiments, the silicone rubber fixing layer has a width of 15-25 mm and a length of 50-200 mm.

In other embodiments, the middle layer (2) is a silicone rubber having a thickness of 0.5-1 mm and a hardness of 10-20 Shore A Hardness.

In other embodiments, the protruding layer (3) is composed of silicone rubber columns of different heights.

In other embodiments, the silicone rubber columns have a diameter of 3-6 mm, a height of 2-8 mm, a width between the silicone rubber columns of 0.5-1.5 mm.

The current technology is invented using the dual effect of pressure and hydration through development a silicone pressure pad comprising a sheet of medical grade of silicone gel sheet and an innovative design of silicone stud sheet with silicone elastic pressure band to provide pressure effect on Hypertrophic scar. This new invention can apply positive pressure as well as hydration effect, thus maximizing its clinical efficacy.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure discloses a medical device for the treatment of scar tissue. One ordinary skill in the art can learn from the contents of this disclosure and appropriately improve the process parameters to achieve the same invention. It is necessary to specially point out that all such alternatives and modifications are obvious to one ordinary skill in the art and are considered to be included in the present disclosure. The method and use of the present disclosure have been described in terms of preferred examples. It will be apparent to those ordinary skills in the art that the methods and applications described herein may be modified or modified and combined to implement and practice the techniques of the present disclosure without departing from the scope of the present disclosure.

In order to further understand the present disclosure, the technical solutions in the examples of the present disclosure will be described clearly and completely herein in conjunction with the examples of the present disclosure. Apparently, the described examples are only a part of the examples of the present disclosure, rather than all examples. Based on the examples in the present disclosure, all of other examples, made by one ordinary skill in the art without any creative efforts, fall into the protection scope of the present disclosure.

In one aspect, the present invention provides a silicone gel sheet, wherein the silicone gel sheet comprises a silicone gel bottom layer (1) , a silicone rubber fixing layer (2, 3) and a silicone elastic pressure band (4) .

In some embodiments, the silicone gel sheet could produce optimal positive pressure of 15-25 mmHg. The special feature of the invention is to provide a combined pressure and silicone gel effect gel dual treatment method that applies a positive pressure to scars and combines silicone gel scar therapy to inhibit hypertrophic scar and achieve the better effect on maturation of scars.

When using, take out the silicone gel sheet, tear off the protective film, fix the sticky silicone gel side on the scar surface, then tear the outer packaging of the silicone elastic pressure band, take out the silicone elastic pressure band. The silicone elastic pressure band is then applied with downward positive pressure to fix the silicone rubber silicone sheet on the skin surface. This product can produce sufficient optimal pressure of 15-25 mmHg to the scar area through a fixed silicone elastic pressure band, combined with the therapy of silicone gel, can better inhibit the growth of scars and make the scars heal. It has a simple structure and is convenient to use.

In some embodiments, the silicone elastic pressure band (4) is a Polyurethane (PU) elastic fabric band coated with a medical grade silicone gel layer.

The silicone elastic pressure band uses a PET film covered with a layer of silicone gel, so as to provide positive pressure for scars with its elasticity and adhesive characteristics. The silicone elastic pressure band can be reused until it becomes less sticky.

In some embodiments, the silicone elastic pressure band (4) has a thickness of less than 0.5 mm and an adhesion of 40-80 N/m.

In some embodiments, the silicone elastic pressure band (4) is longer and wider than the silicone rubber fixing layer.

The pressure generated on the object is inversely proportional to the radius of curvature of the object. The use of Medical Grade Silicone Gel sheet with Pressure technology could change the surface curvature of the object to a smaller radius, thus creating a higher pressure on the object. For example: the upper leg has a flat surface with larger radius of curvature, after adding the new silicone gel sheet, it will reduce the radius of curvature, thus creating a larger gradient of pressure with the same amount of force added on the object (as shown in figure 3) .

In some embodiments, the silicone gel bottom layer (1) has a width of 15-25mm and a length of 50-200 mm according to the length of the scar tissue prescribed.

In some embodiments, the silicone gel bottom layer (1) has a thickness of 0.5-2 mm, a hardness of 0-1 Shore A Hardness and an adhesion of 10-20 N/m, a width of 15-25mm and a length of 50-200 mm according to the length of the scar tissue prescribed

In other embodiments, the protruding layer (3) is composed of cylindrical silicone rubber columns.

In other embodiments, the protruding layer (3) is composed of cylindrical silicone rubber columns of different heights.

It uses a silicone rubber cylindrical column of different heights as the fixing layer, with the theory of Laplace Law, to produce sufficient positive pressure to the scar, the bottom layer is medical grade silicone gel, which is used to smooth and mature scars.

In other embodiments, the protruding layer (3) is composed of cylindrical silicone rubber columns having a diameter of 3-6 mm, a height of 2-8 mm, a width between the silicone rubber columns of 0.5-1.5 mm.

The present invention can apply additional pressure to the scar by the newly developed silicone gel sheet with rubber stud on top, combined with additional application of silicone elastic pressure band can better inhibit the growth of scars. This is simple and easy to apply. A study by Professor Cecilia Li-Tsang and her research team found that the combination of pressure therapy and silicone therapy treatment could generate more significant outcomes than just one single intervention alone.

Unless otherwise stated, all the reagents in the examples of the present disclosure are commercial products, which can be purchased on the market.

Unless otherwise stated, “PU” used herein refers to Polyurethane plastic.

Unless otherwise stated, “PET” used herein refers to Polyethylene terephthalat.

Unless otherwise stated, “medical grade” used herein refers to medical grade excipients or raw materials that can be used in the pharmaceutical process.

Unless otherwise stated, the parameters expressed in numerical ranges, such as 0-1, 1-2, 50-200, refer to the range of 0 to 1, the range of 1 to 2, the range of 50 to 200 respectively.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within this disclosure. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within this disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in this disclosure.

It must be noted that as used herein and in the appended claims, the singular forms “a” , “an” , and “the” include plural referents unless the context clearly dictates otherwise.

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, which are intended to be read in conjunction with both this Summary, the detailed description and any preferred and/or particular embodiments specifically discussed.

BRIEF DESCRIPTION OF DRAWINGS

In order to illustrate the technical solutions in the embodiments of the present disclosure or the conventional arts more clearly, the drawings used for illustrating the examples or the conventional arts will be described briefly hereinafter.

Figure 1 is a schematic diagram of the cross-sectional structure of embodiment 1 of the present invention. Silicone gel bottom layer (1) , Middle layer (2) of the silicone rubber fixing layer to hold the coating of silicone gel, Protruding layer (3) of various height of cylindrical studs column; Outer layer of silicone elastic Pressure band (4) ; the silicone gel bottom layer (1) is medical grade silicon gel.

Figure 2 is the distribution of low (3A) and high (3B) cylindrical studs column above the fixing sheet; the low cylindrical studs column (3A) are on the side, the high cylindrical suds column (3B) are in the middle.

Figure 3 is the pressure diagram generated on the object that is inversely proportional to the radius of curvature of the object.

Figure 4 is a schematic view of the longitudinal section structure of the second embodiment of the present invention. Silicone gel bottom layer (1) , Middle layer (2) of the silicone rubber fixing layer to hold the coating of silicone gel, Protruding layer (3) of various height of cylindrical studs column (3A stud at side, 3B middle stud) ; Outer layer of silicone elastic Pressure band (4) .

Figure 5 is the top view of silicone elastic Pressure Band and the Silicone Rubber Gel sheet which depicts the relative size of outer layer silicone elastic Pressure Band vs the inside layers of silicone Rubber Gel sheet. (1) Silicone Gel sheet with cylindrical studs columns; (2) silicone elastic Pressure Band; (3) The width is equal to the width of the silicone gel sheet layer; (4) The length is 25-50mm.

EXAMPLES

The above are only preferred examples of the present disclosure, but the embodiments of the present invention are not limited to the above examples, any other changes, modifications, substitutions, combinations, and simplifications made without departing from the principles of the present disclosure should be considered as within the protection scope of the present disclosure.

Example

As shown in the front view of Figure 1 and the side view of Figure 4 , the Medical Grade Silicone Gel sheet with Pressure technology of the present invention includes:

(1) . Bottom layer of Medical grade silicone gel;

(2) Middle layer of fixing sheet to hold the coating of silicone gel;

(3) Fixing layer of various height of cylindrical studs column;

(4) Outer layer of silicone elastic Pressure band.

When using, take out the silicone rubber silicone sheet, tear off the protective film, fix the silicone rubber silicone sheet on the scar surface, then tear the outer packaging of the silicone elastic pressure band, take out the silicone elastic pressure band. The silicone elastic pressure band is applied with downward positive pressure to fix the silicone rubber silicone sheet on the skin surface. This product can produce sufficient positive pressure of 15-25 mmHg to the scar area through a fixed silicone elastic pressure band, combined with the therapy of silicone gel, can better inhibit the growth of scars and make the scars heal. It has a simple structure and is convenient to use.

Trial report on Medical Grade Silicone Gel sheet with Pressure technology.

Background: The development of hypertrophic scar has been regarded as one of the major medical problems after burns and trauma in Asia. Pressure therapy has been widely used to control hypertrophic scars (HS) since the early 1970s; however, using pressure garments alone may not be effective enough to provide therapeutic pressure on some body parts, such as the face, finger webs, chest etc. Hence, the present study is designed to investigate the Medical Grade Silicone Gel sheet with Pressure technology for the scar conditions for various causes of scar formation. With pressure monitored, this study aims to find out the effectiveness of Medical Grade Silicone Gel sheet with Pressure technology in controlling hypertrophic scars conditions over time.

Methodology: A single group pretest-posttest design and convenient sampling method was adopted in this study. A total of 84 cases with burnt hypertrophic scar (40%) , surgical hypertrophic scar (31.2%) , keloidal scar (27.1%) , trauma cased hypertrophic scar (1.8%) were recruited from hospitals clinics and at the university campus. 32 males and 52 females with a mean age of 43.02 ± 18.54 years. Recruited subjects would be assessed by two certified Occupational Therapists before intervention and three months post-intervention. A set of silicone rubber silicone sheet with several pieces of pressure band were provided for each subject. Subjects would be instructed to wear the silicone rubber silicone sheet with pressure band for 2 hours a day on the first day and a 2 hours increment every other day until the total wearing time reached 20+ hours per day. Subjects would also be instructed to clean the silicone rubber silicone sheet and pressure band once/twice a day for hygienic measure.

Result: A Wilcoxon Signed Rank Test revealed a statistically significant reduction in the hypertrophic scars’ pigmentation (p < . 006) , vascularity (p < .000) , pliability (p < . 000) , and hight (p < . 000) in mVSS, itchiness level (p < .000) , and elasticity (p < . 000) ; and a significant difference in mVSS total score (p < . 000) in paired t-test. The pain level showed a decreased trend, and thickness from the diagnostic ultrasound increased after three months of treatment. Patients'feedback questionnaire was performed with a ten point scale with zero indicated negative feedback, and ten indicated positive feedback of their perception on Medical Grade Silicone Gel sheet with Pressure technology application. Overall, the patients’ perspective for the Medical Grade Silicone Gel sheet with Pressure technology were 7 or above excepted Q7 (displacement of pressure band during large body movement) was 6, which means the Medical Grade Silicone Gel sheet with Pressure technology would have medium shifting when patients were doing large body movements, such as climbing upstairs or exercising. The majority of patients gave a high satisfaction score for the smell, easy to clean, and good fixability when doing small body movements. From the feedback of the two therapists, the scores were higher (above 7) , except for the price. The highest score is the durability of the silicone rubber silicone sheet and pressure band, which was very similar to the response from the patients. By the clinical observation from the therapists, the effectiveness of the Medical Grade Silicone Gel sheet with Pressure technology for the burnt HS was more significant than the surgical scar and keloidal scar.

Conclusion: The Medical Grade Silicone Gel sheet with Pressure technology shows to be an effective tool in managing HS/Keloidal scar and decrease the scar pigmentation, vascularity, pliability, thickness, and itchiness of the scar after three months of intervention. Patients and therapists perceived the Medical Grade Silicone Gel sheet with Pressure technology to be an effective, comfortable, easy-to-use, and durable product.

Reference throughout this specification to “an embodiment” , “one embodiment” , “some embodiments” , “an example, ” “a specific example, ” or “some examples, ” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as “in some embodiments, ” “in one embodiment” , “in an embodiment” , “in another example, “in an example, ” “in a specific example, ” or “in some examples, ” in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure.

Claims

A silicone gel sheet, wherein the silicone gel sheet comprises a silicone gel bottom layer (1) , a silicone rubber fixing layer (2, 3) and a silicone elastic pressure band (4) .
The silicone gel sheet of claim 1, wherein the silicone elastic pressure band (4) is a PU or PE elastic fabric band coated with a medical grade silicone gel layer.
The silicone gel sheet of claim 1, wherein the silicone elastic pressure band (4) has a thickness of less than 0.5 mm and an adhesion of 40-80 N/m.
The silicone gel sheet of claim 1, wherein the silicone elastic pressure band (4) is longer and wider than the silicone rubber fixing layer.
The silicone gel sheet of any one of claims 1 to 4, wherein the silicone gel bottom layer (1) has a thickness of 0.5-2 mm, a hardness of 0-1 Shore A Hardness and an adhesion of 10-20 N/m.
The silicone gel sheet of any one of claims 1 to 4, wherein the silicone rubber fixing layer comprises a middle layer (2) and a protruding layer (3) .
The silicone gel sheet of claim 6, wherein the silicone rubber fixing layer has a width of 15-25 mm and a length of 50-200 mm.
The silicone gel sheet of claim 6, wherein the middle layer (2) is a silicone rubber having a thickness of 0.5-1 mm and a hardness of 10-20 Shore A Hardness.
The silicone gel sheet of claim 6, wherein the protruding layer (3) is composed of silicone rubber columns of different heights.
The silicone gel sheet of claim 9, wherein the silicone rubber columns have a diameter of 3-6 mm, a height of 2-8 mm, a width between the silicone rubber columns of 0.5-1.5 mm.