Melatonin/Sericin Wound Healing Patches: Implications for Melanoma Therapy.

Melatonin and sericin exhibit antioxidant properties and may be useful in topical wound healing patches by maintaining redox balance, cell integrity, and regulating the inflammatory response. In human skin, melatonin suppresses damage caused by ultraviolet radiation (UVR) which involves numerous mechanisms associated with reactive oxygen species/reactive nitrogen species (ROS/RNS) generation and enhancing apoptosis. Sericin is a protein mainly composed of glycine, serine, aspartic acid, and threonine amino acids removed from the silkworm cocoon (particularly Bombyx mori and other species). It is of interest because of its biodegradability, anti-oxidative, and anti-bacterial properties. Sericin inhibits tyrosinase activity and promotes cell proliferation that can be supportive and useful in melanoma treatment. In recent years, wound healing patches containing sericin and melatonin individually have attracted significant attention by the scientific community. In this review, we summarize the state of innovation of such patches during 2021-2023. To date, melatonin/sericin-polymer patches for application in post-operational wound healing treatment has been only sparingly investigated and it is an imperative to consider these materials as a promising approach targeting for skin tissue engineering or regenerative dermatology.

Development and Application of an Advanced Biomedical Material-Silk Sericin.

Sericin, a protein derived from silkworm cocoons, is considered a waste product derived from the silk industry for thousands of years due to a lack of understanding of its properties. However, in recent decades, a range of exciting properties of sericin are studied and uncovered, including cytocompatibility, low-immunogenicity, photo-luminescence, antioxidant properties, as well as cell-function regulating activities. These properties make sericin-based biomaterials promising candidates for biomedical applications. This review summarizes the properties and bioactivities of silk sericin and highlights the latest developments in sericin in tissue engineering and regenerative medicine. Furthermore, the extended application of sericin in developing flexible electronic devices and 3D bioprinting is also discussed. It is believed that sericin-based biomaterials have great potential of being developed into novel tissue engineering products and smart implantable devices for various medical applications toward improving clinical outcomes.

Anti-inflammatory effects of sericin and swimming exercise in treating experimental Achilles tendinopathy in rat.

The aim of this study was to assess the effectiveness of combining sericin with swimming exercise as a treatment for type-I collagenase-induced Achilles tendinopathy (AT) in rats, with a focus on inflammatory cytokines. An experimental AT model was established using type-I collagenase in male Sprague-Dawley rats, categorized into five groups: Group 1 (Control + Saline), Group 2 (AT), Group 3 (AT + exercise), Group 4 (AT + sericin), and Group 5 (AT + sericin + exercise). Intratendinous sericin administration (0.8 g/kg/mL) took place from days 3 to 6, coupled with 30 min daily swimming exercise sessions (5 days/week, 4 weeks). Serum samples were analyzed using ELISA for tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), interleukin-10 (IL-10), and total antioxidant-oxidant status (TAS-TOS), alongside histopathological and immunohistochemical assessments of Achilles tendon samples. Elevated TNF-α and IL-1ß and decreased IL-10 levels were evident in Group 2; Of these, TNF-α and IL-1ß were effectively reduced and IL-10 increased across all treatment groups, particularly groups 4 and 5. Serum TAS was notably lower in Group 2 and significantly increased in Group 5 compared to Group 2. Histopathologically, Group 2 displayed severe degeneration, irregular fibers, and round cell nuclei, while Group 5 exhibited decreased degeneration and spindle-shaped fibers. The Bonar score increased in Group 2 and decreased in groups 4 and 5. Collagen type-I alpha-1 (Col1A1) expression was notably lower in Group 2 (P = 0.001) and significantly increased in groups 4 and 5 compared to Group 2 (P = 0.011 and 0.028, respectively). This study underscores the potential of sericin and swimming exercises in mitigating inflammation and oxidative stress linked to AT pathogenesis, presenting a promising combined therapeutic strategy.

Toxicological effects of dimethlybenzeneanthracene in Balb C mice and pharmacological intervention by silk sericin-conjugated silver nanoparticles.

Polycyclic aromatic hydrocarbons (PAHs) such as 7, 12-dimethylbenzneanthracene (DMBA), due to long-term bioaccumulation cause serious physiological processes and behavioral dysfunctions such as cancer, ageing, and hypertension. Silk sericin (SS) is instrumental in cancer applications due to presence of flavonoids and carotenoids which are natural pigments, present in the layer of sericin that has antioxidant and antityrosinase activity. It reduces oxidative stress and suppresses cancer cytokines while interacting with reactive oxygen species (ROS) to stand against lipid peroxidation. Recent research was focused to calculate the pharmacological intervention of sericin-conjugated silver nanoparticles (S-AgNO3 NPs) against DMBA-induced toxicity. For this purpose, SS protein was extracted from silkworm cocoons by degumming process and the prepared S-AgNO3 NPs via a green synthesis. In female albino mice, a total of 50 mg/kg oral administration of DMBA was used for the induction of toxicity which required almost 8 to 10 weeks approximately. After 60 days of experimentation, mice were dissected, blood samples were collected for further hematological and biochemical analysis and were euthanized via cervical dislocation. There was a significant rise in the level of red blood cells, platelets, lymphocytes, and hemoglobin at the highest applied concentration of sericin and its nanoparticles. Similarly, a reasonable decline was observed in the level of white blood cells, neutrophils, eosinophils, and monocytes as compared to the cancer-inducing group. The level of glutathione, lactate dehydrogenase, and alkaline phosphatase as well as immunoglobulins such as immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) were significantly reduced in all treatment groups as compared to the DMBA-induced group. Substantial effects were demonstrated in response to S-AgNO3 NPs II (T) at the highest concentrations (200 mg/kg, BW) as follows: glutathione (2.42 ± 0.26 µmol/L), lactate dehydrogenase (493.6 ± 5.78 U/L), alkaline phosphatase (158.4 ± 6.35 U/L), IgA (4.22 ± 0.19 g/L), IgG (70 ± 1.70 g/L), and IgM (4.76 ± 0.12). The histopathological study of the liver, kidneys, and brain revealed that the DMBA-induced group showed cytotoxic effects against all selected organs of mice that were recovered by treatment of selective compounds but highly effective recovery was seen in S-AgNO3 NPs II (T). These results concluded that silk S-AgNO3 NPs showed significant pharmacological potential against cancer-inducing toxicity.

Sericin as treatment of obesity: morphophysiological effects in obese mice fed with high-fat diet / Sericina como tratamento da obesidade: efeitos morfofisiológicos de camundongos obesos por dieta hiperlipídica

ABSTRACT Objective To investigate the effects of sericin extracted from silkworm Bombyx mori cocoon on morphophysiological parameters in mice with obesity induced by high-fat diet. Methods Male C57Bl6 mice aged 9 weeks were allocated to one of two groups - Control and Obese, and fed a standard or high-fat diet for 10 weeks, respectively. Mice were then further subdivided into four groups with seven mice each, as follows: Control, Control-Sericin, Obese, and Obese-Sericin. The standard or high fat diet was given for 4 more weeks; sericin (1,000mg/kg body weight) was given orally to mice in the Control-Sericin and Obese-Sericin Groups during this period. Weight gain, food intake, fecal weight, fecal lipid content, gut motility and glucose tolerance were monitored. At the end of experimental period, plasma was collected for biochemical analysis. Samples of white adipose tissue, liver and jejunum were collected and processed for light microscopy analysis; liver fragments were used for lipid content determination. Results Obese mice experienced significantly greater weight gain and fat accumulation and had higher total cholesterol and glucose levels compared to controls. Retroperitoneal and periepididymal adipocyte hypertrophy, development of hepatic steatosis, increased cholesterol and triglyceride levels and morphometric changes in the jejunal wall were observed. Conclusion Physiological changes induced by obesity were not fully reverted by sericin; however, sericin treatment restored jejunal morphometry and increased lipid excretion in feces in obese mice, suggesting potential anti-obesity effects.

RESUMO Objetivo Investigar os efeitos da sericina extraída de casulos de Bombyx mori na morfofisiologia de camundongos com obesidade induzida por dieta hiperlipídica. Métodos Camundongos machos C57Bl6, com 9 semanas de idade, foram distribuídos em Grupos Controle e Obeso, que receberam ração padrão para roedores ou dieta hiperlipídica por 10 semanas, respectivamente. Posteriormente, os animais foram redistribuídos em quatro grupos, com sete animais cada: Controle, Controle-Sericina, Obeso e Obeso-Sericina. Os animais permaneceram recebendo ração padrão ou hiperlipídica por 4 semanas, período no qual a sericina foi administrada oralmente na dose de 1.000mg/kg de massa corporal aos Grupos Controle-Sericina e Obeso-Sericina. Parâmetros fisiológicos, como ganho de peso, consumo alimentar, peso das fezes em análise de lipídios fecais, motilidade intestinal e tolerância à glicose foram monitorados. Ao término do experimento, o plasma foi coletado para dosagens bioquímicas e fragmentos de tecido adiposo branco; fígado e jejuno foram processados para análises histológicas, e amostras hepáticas foram usadas para determinação lipídica. Resultados Camundongos obesos apresentaram ganho de peso e acúmulo de gordura significativamente maior que os controles, aumento do colesterol total e glicemia. Houve hipertrofia dos adipócitos retroperitoneais e periepididimais, instalação de esteatose e aumento do colesterol e triglicerídeos hepáticos, bem como alteração morfométrica da parede jejunal. Conclusão O tratamento com sericina não reverteu todas as alterações fisiológicas promovidas pela obesidade, mas restaurou a morfometria jejunal e aumentou a quantidade de lipídios eliminados nas fezes dos camundongos obesos, apresentando-se como potencial tratamento para a obesidade.