Advances in aquatic bio-inspired medical adhesives / 生物医学工程学杂志

In recent years, due to the dramatic increase in the number of surgical operations, there has been a clinically significant increase in the demand for medical adhesives capable of cohesion in a moist environment that can overcome blood or tissue fluids . As the understanding of the mechanisms and key elements of natural adhesion to aquatic organisms continues to develop, a variety of medical adhesives have been developed by mimicking adhesion procedures or utilizing key functional groups. This article will review the classification, adhesion mechanism, use, research progress and development prospects of biomedical adhesives inspired by aquatic organisms octopus and mussels.

Tetramethylpyrazine Improves Postoperative Tissue Adhesion: A Drug Repurposing / 中国结合医学杂志

Plants are known to possess plenty of pharmacological activities as a result of various phytoconstituents. Tetramethylpyrazine (TMP), one of the most widely used medicinal compound isolated from traditional Chinese herb, is usually employed for anti-oxidation, anti-inflammation, anti-platelet aggregation, anti-lipid, anti-fibrosis, as well as activating blood, removing stasis, dilating small arteries, improving microcirculation and antagonizing calcium. In the present paper, the anti-adhesion effect of TMP were reviewed. TMP was found to play a multi-target and muti-link role in anti-adhesion by inhibiting hyperplasia of collagen and overexpression of adhesion-related factors and reducing the concentration of white blood cells and fibrin in plasma. Because previous studies mostly focused on in vitro experiments and animal experiments, there is an urgent need for clinical research with abundant indicators to further prove its anti-adhesion potency. Future basic research should concentrate on the development of TMP as a biological material.

Reconstruction of the orbital wall using superior orbital rim osteotomy in a patient with a superior orbital wall fracture / 대한악안면성형재건외과학회지

BACKGROUND: Fractures of the orbital wall are mainly caused by traffic accidents, assaults, and falls and generally occur in men aged between 20 and 40 years. Complications that may occur after an orbital fracture include diplopia and decreased visual acuity due to changes in orbital volume, ocular depression due to changes in orbital floor height, and exophthalmos. If surgery is delayed too long, tissue adhesion will occur, making it difficult to improve ophthalmologic symptoms. Thus, early diagnosis and treatment are important. Fractures of the superior orbital wall are often accompanied by skull fractures. Most of these patients are unable to perform an early ocular evaluation due to neurosurgery and treatment. These patients are more likely to show tissue adhesion, making it difficult to properly dissect the tissue for wall reconstruction during surgery. CASE PRESENTATION: This report details a case of superior orbital wall reconstruction using superior orbital rim osteotomy in a patient with a superior orbital wall fracture involving severe tissue adhesion. Three months after reconstruction, there were no significant complications. CONCLUSION: In a patient with a superior orbital wall fracture, our procedure is helpful in securing the visual field and in delamination of the surrounding tissue.

A study of the vitreoretinal interface in patients with age-related macular degeneration / Estudo da interface vitreorretiniana em pacientes com degeneração macular relacionada à idade

ABSTRACT Purpose: To assess whether hyaloid adhesion is more prevalent in patients with age-related macular degeneration (AMD) than in control patients and to evaluate whether it is more prevalent in exudative AMD than in non-exudative AMD. Methods: This was a cross-sectional, controlled analytical study. Patients from the Ophthalmology Department of the Public Service Hospital of the State of São Paulo were included if they were diagnosed with AMD that was confirmed by fundus biomicroscopy and fluorescein angiography. Patients were divided into three groups: patients without a vitreoretinal disease (controls), patients with exudative AMD, and patients with non-exudative AMD. For the optimal study of the vitreoretinal interface, all patients were subjected to spectral-domain optical coherence tomography (SD-OCT; Cirrus HD-OCT, version 4000; Carl Zeiss Meditec) and ultrasonography (UltraScan®, Alcon). Results with p values of ≤0.05 were considered statistically significant. Results: We assessed 75 eyes of 23 patients with AMD (14 women and nine men) and 15 the control patients (11 women and four men). In total, 33 eyes had AMD that was consistent with the inclusion criteria, of which 11 had the non-exudative form (non-atrophic) and 22 had the exudative form (11 active and 11 disciform scars). Adherence was observed in eight eyes in the control group (26.67%), in seven eyes with exudative AMD (31.82%), and in five eyes with non-exudative AMD (45.45%). Conclusion: Patients with exudative and non-exudative forms of AMD did not present with higher vitreoretinal adhesion than control patients as assessed by SD-OCT and ultrasound. Moreover, patients with exudative AMD (neovascular membrane and disciform scar) did not reveal a higher adherence than those with non-exudative AMD when evaluated by the same methods.

RESUMO Objetivo: Avaliar se a adesão hialoidea é mais prevalente em pacientes com degeneração macular relacionada a idade (DMRI) (exsudativa e não exsudativa) comparado ao grupo controle e avaliar se a prevalência é maior na forma exsudativa comparada a forma não exsudativa. Métodos: Trata-se de um estudo transversal, analítico, de grupo controle, com os pacientes atendidos no Departamento de Retina do Serviço de Oftalmologia do Hospital do Servidor Público Estadual de São Paulo (HSPE), que tiveram o diagnóstico de DMRI confirmado após a biomicroscopia de fundo e angiofluoresceinografia. Os pacientes foram divididos em três grupos, um composto por pacientes sem doenças vitreorretinianas (30 olhos), outro pacientes com DMRI exsudativa (22 olhos) e o terceiro grupo por pacientes com DMRI não exsudativa (11 olhos). Para melhor estudo da interface vitreorretiniana, todos os pacientes foram submetidos aos exames de SD-TCO (Cirrus HD-TCO, versão 4000; Carl Zeeis Meditec) e ultrassonografia (UltraScan®, Alcon). Foram considerados significativos os resultados com valor de p≤0,05. Resultados: Foram avaliados 75 olhos de 23 pacientes com DMRI e 15 no grupo controle, sendo que apenas 33 olhos que apresentavam DMRI obedeciam aos critérios de inclusão, sendo 11 pertencentes à forma seca (nenhuma forma atrófica) e 22 à forma exsudativa (11 de forma ativa e 11 disciforme). A adesão foi encontrada em oito olhos no grupo controle (26,67%), em sete olhos com DMRI exsudativa (31,82%) e em cinco olhos no grupo DMRI não exsudativa (45,45%). Conclusão: Neste estudo, pacientes com DMRI (formas exsudativa e não exsudativa) não apresentaram maior adesão vitreorretiniana quando comparados ao grupo controle, ao serem avaliados através SD-TCO (Cirrus HD-TCO, versão 4000; Carl Zeeis Meditec) e ultrassonografia (UltraScan®, Alcon). Neste estudo, pacientes com DMRI exsudativa (ativa e disciforme) não apresentaram maior adesão quando comparados à forma seca, ao serem avaliados pelos mesmos métodos.

Construction of deep flexor tendon transection models:peritenon transplantation prevents tendon adhesions / 中国组织工程研究

BACKGROUND:The adhesion between muscle tendon and surrounding tissue after tendon restoration is one hot topic in clinic. OBJECTIVE:To construct a deep flexor tendon transection model in the third toe of female Leghorn chicken and to explore the effect of peritenon transplantation on the prevention of tendon adhesions. METHODS:After the transection models were successful y established, the third toe of left claw was taken as experimental group A. The transected tendon was sutured, the tendon anastomosis end was wrapped with the peritenon of the deep flexor tendon from the ipsilateral fourth toe (experimental group B). The third toe of right claw served as control group A, the transfected tendon was sutured and restored with the peritenon. The fourth toe of right claw was taken as control group B. Gross observation and histological observation of the tendon were performed. RESULTS AND CONCLUSION:At 28 days postoperatively, gross observation and histological observation of Leghorn chicken were performed and compared using the Kruskal-Wal isH and Nemenyi test, respectively. The results showed that, the therapeutic effect was better in experimental group A than in control group A (P0.05). The flexor function was evaluated and compared with the least significant difference t-test. The results showed that the postoperative effect was better in experimental group A than in control group A (P0.05). Peritenon transplantation can effectively prevent tendon adhesions and has little impact on normal tendon sliding.

Fibrin Glue Fixation for Suction Blister Epidermal Grafting in Two Patients with Stable Vitiligo

Vitiligo is a chronic disorder characterized by depigmented macules which can slowly enlarge with the concurrent development of new lesions. Although autologous suction blister epidermal grafting is an established technique for the treatment of recalcitrant, stable vitiligo, the donor tissue graft is not easy to fix at the recipient site, especially in areas such as the joints, face, cutaneous folds, hands, feet, and hair-bearing areas. Therefore, various methods of donor tissue fixation have been attempted. We report two cases of vitiligo treated with suction blister epidermal grafting, with fibrin tissue adhesion. The first case is that of 16-year-old female patient presented with hypopigmented patches on the forehead and frontal scalp area. The other case is that of 32-year-old female patient presented with hypopigmented patches on the chin. We treated them with phototherapy for 1~4 years; however, the lesions were recalcitrant. Therefore, we tried treatment with a suction blister epidermal graft. Because graft fixation is difficult at the recipient sites, fibrin glue was sprayed on the grafts. Thereafter, we applied a porous silicone wound contact layer over the graft area and applied sterile gauze dressing that was left for a week. One week after the procedure, firm fixation of the donor tissue was observed in both cases. Fibrin glue seemed to improve the graft fixation, providng protection against infection and an optimal environment for wound healing. This report suggests that the application of an epidermal graft with fibrin glufixation, can provide the best result in the surgical treatment of stable vitiligo.

Análise das aderências resultantes da fixação de telas cirúrgicas com selantes de fibrina e sutura: modelo experimental intraperitoneal / Analysis of adhesions resulted from mesh fixation with fibrin sealant and suture: experimental intraperitoneal model

OBJETIVO: Comparar fixação cirúrgica de telas de polipropileno (PP) e telas de polipropileno revestido (PCD), usando fio de sutura de polipropileno e cola biológica, quanto à formação de aderências intraperitoneais. MÉTODOS: Amostra de 46 ratas Wistar, randomizadas em seis grupos: dois grupos-controle, com cinco ratas cada, que foram submetidos um à incisão medial (IM) e o outro à uma incisão em forma de U (IU); nenhum desses grupos recebeu tela. Dois grupos com tela de PP, um com dez ratas, fixada com sutura (PPF), e o outro, com seis ratas, fixada com cola biológica (PPC). E Dois grupos com tela de PCD, no primeiro, com dez animais, a tela foi fixada com sutura (PCDF), e no segundo, com dez animais, com cola biológica (PCDC). RESULTADOS: Após o prazo de 21 dias, os grupos-controle não apresentaram aderências significantes. O grupo PPC apresentou menor grau de aderência do que o grupo PPF (p=0,01). Não houve diferença entre as fixações nos grupos com PCD. CONCLUSÃO: A comparação da fixação apresentou diferença estatística significativa apenas à tela de PP, com menor grau de aderência utilizando a cola. As aderências se localizaram predominantemente nas extremidades das telas estudadas.

OBJECTIVE: To compare surgical fixation of polypropylene mesh (PP) and coated polypropylene mesh (PCD) using polypropylene suture and fibrin glue, as for the formation of intraperitoneal adhesions. METHODS: A sample of 46 female Wistar rats were randomized into six groups: two control groups, with five rats each, were subjected to one medial incision (MI) and the other to a U-shaped incision (UI), none of these groups received the mesh. Two groups of PP mesh, with ten rats, fixed with suture (PPF), the other with six rats, fixed with biological glue (PPC). And two groups of PCD mesh, at first, with ten animals, the mesh was fixed with sutures (PCDFs) and the second with ten animals with biological glue (PCDC). RESULTS: After 21 days, the control groups showed no significant adhesions. The PPC group showed a lower degree of adhesion than the PPF group (p = 0.01). There was no difference between the groups with PCD. CONCLUSION: Comparison of fixation was statistically different only with PP mesh, with lesser degrees of adherence when using the glue. Adhesions were predominantly located at the extremities of the meshes studied.

Anti-Adhesive Effect of GUARDIX-SL(R) after Intact Canal Wall Mastoidectomy: Preliminary Study

BACKGROUND AND OBJECTIVES: Adhesion of middle ear and mastoid cavity after mastoidectomy represents a potential source of surgical failure. GUARDIX-SL(R), absorbable anti-adhesive material, which is composed of sodium hyaluronate and sodium carboxymethyl cellulose, is an effective agent that widely used as a surgical adjuvant to decrease adhesion in the surgery. Therefore, we evaluated the clinical efficacy of the GUARDIX-SL(R) for the prevention of adhesion after mastoidectomy. SUBJECTS AND METHODS: This study was randomized and double-blinded. Conventional intact canal wall mastoidectomy was conducted in both control (n=14) and study group (n=10). To avoid bias because of different surgeons, we only included patients who were operated on by one surgeon. In the study group, 1.5 g GUARDIX-SL(R) was applied in the mastoid cavity at the end of mastoidectomy. To evaluate anti-adhesive effect of GUARDIX-SL(R), the volume of aerated area in the mastoid cavity was calculated and compared with temporal bone computed tomography performed at preoperatively and postoperatively. Besides, to assess the success of operation, pure tone audiometry was also performed at preoperatively and postoperatively. RESULTS: The volume of aerated area of mastoid cavity after mastoidectomy was more increased in GUARDIX-SL(R) group, but was not statistically significant in the GUARDIX-SL(R) group than the control. And all results of pure tone audiometry satisfied the criteria of successful operation which has been suggested by Otological Society of Korea. CONCLUSION: The results suggest that GUARDIX-SL(R) may be an efficacious and safe material in decreasing the incidence of adhesion after mastoidectomy.

Effect of Amniotic Membrane Transplantation on Tissue Adhesion in Flexor Tenorrhaphy of Chicken / 대한정형외과학회잡지

PURPOSE: The role of the amniotic membrane with or without radiation was investigated with regard to preventing adhesion after flexor tenorrhaphy of chicken. MATERIALS AND METHODS: Nine chicken were divided into three groups. The second flexor tendon of the chicken was operated on. In group A, the flexor tendon was excised and one half and the tendon was repaired. In group B, the repaired tendon was covered with an amniotic membrane. In group C, the repaired tendon was covered with a lyophilised and 25 kGy irradiated amniotic membrane. The gross and histology findings on the level of inflammation and fibrosis of the repaired tendon were evaluated at 3, 6 and 9 weeks after surgery. RESULTS: Group C had the least inflammatory cell infiltration and fibroblast proliferation at any time. CONCLUSION: The use of radiated amniotic membrane was effective in preventing inflammation and adhesion after flexor tenorrhaphy in chickens.

Adhesion between Amniotic Membrane and Retinal Tissue and Inhibition of Amniotic Membrane on Cell Transformation

PURPOSE: Tissue adhesion rate between the amniotic membrane and the retinal tissue and histological change of the retinal tissue was studied. And the inhibition effect of amniotic membrane on the retinal pigment epithelial cell transformation was evaluated. METHODS: The human amniotic membrane and the porcine retinal tissue flap were used. The sensory retinal flap and the retinal pigment epithelial flap were placed on the amniotic membrane in culture disk. Tissue adhesion was evaluated and graded at 1, 2, 3, 4 and 5 weeks. Glial fibrillary acidic protein immunohistochemical staining and Masson's trichrome staining were performed for histologic study. Transmitted electron microscope examination was performed to study the stabilization effects of amniotic membrane. RESULTS: Tissue adhesion rates showed no significant change until the 4th week, but tend to decrease in the 5th week of organotissue culture. Tissue adhesion rate was higher in the chorion-side than in the amnion-side culture (p=0.000) and was higher in the retinal pigment epithelial than in the retinal flap (p=0.000). The inhibition of cell transformation was higher in the chorion-side culture than in the amnion-side culture. CONCLUSIONS: Amniotic membrane can be used for prevention of proliferative vitreoretinopathy by its mechanical barrier effect and cell stability effect.

Availability of Polyethylene Film for Reduction of Postoperative Adhesion in Adjustable Strabismus Surgery in Rabbits

Adjustable strabismus surgery sometimes fails because of changes in the angle of deviation which develops a few days after surgery. Therefore, the delayed adjustment was recommended; however, the postoperative tissue adhesion disturbed this delayed adjustment. We studied 20 eyes of 10 rabbits; adjustable strabismus surgery was performed on each of the right lateral rectus muscles by hemichangback technique for control study and the surgery on each left lateral rectus muscle was performed by same methods using polyethylene film. The polyethylene film was wrapped around the muscle allowing it to be placed between the muscle and sclera, and between the muscle and cojunctiva. The mean duration of postoperative tissue adhesion was 1.6 +/- 0.70 days in control group and 18.7 +/- 7.09 days in polyethylene group. These results suggested that the use of polyethylene film provides a valuable resource to defer the adjustment by preventing the postoperative tissue adhesion.