CpG methylation changes in Alu repetitive sequences in normal aging due to diastolic hypertension in human dermal fibroblasts from the facial area.

Aging fibroblasts, an important factor contributing to skin aging, are affected by numerous mechanisms, including alterations in DNA methylation and age-related diseases. The current study aimed to investigate the role of Alu methylation in aging fibroblasts and hypertension. The Alu methylation levels in dermal fibroblasts obtained from patients of different ages and blood pressure status were analyzed using the combined bisulfite restriction analysis technique. An inverse correlation was observed between Alu methylation in dermal fibroblasts and patient age. Dermal fibroblasts from the high-normal diastolic blood pressure group had higher Alu methylation levels compared with those from the normal group. The findings of the present study suggest that Alu methylation alterations can be observed with chronological aging and hypertension, and are a potential aging marker or therapeutic target.

Evaluation of P53 immunostaining in patients with cutaneous melanoma.

P53 is a tumor suppressor gene that is mutated in numerous types of cancer. The aim of the present study was to determine the frequency of this mutation in cutaneous melanomas and to conduct clinicopathological characteristics and clinical outcome association analyses with the P53 mutation. P53 immunohistochemical staining was used as a surrogate marker for P53 mutation analysis to assess P53 status. In the present study, 50 pathological samples of cutaneous melanoma from 2012 to 2018 at Chulalongkorn University (Bangkok, Thailand), were subjected to anti-P53 immunohistochemistry, followed by an examination of the association between P53 statuses and clinical and pathological characteristics, along with clinical outcomes. A positive staining for anti-P53 antibody was detected in 30% of patients (15/50) with cutaneous melanomas. Positivity was significantly associated with female sex, nodular histological subtype and Breslow level 4. Cox regression analysis revealed that an age >65.5 years and Breslow grade 4 disease were associated with mortality. The Kaplan-Meier curve revealed a shorter duration of recurrence time in the P53 mutation than P53 wild type. In the present study, P53 mutations in specific cases of cutaneous melanoma were identified. Notably, patients who were older and/or had a Breslow score of 4 exhibited an increased risk of mortality. These findings suggested the potential involvement of P53 mutations in cutaneous melanoma, highlighting the necessity for further investigations to improve understanding of their roles.

Effects of Probiotics on Chemotherapy-induced Diarrhea.

Chemotherapy-induced diarrhea (CID) is a common adverse event in cancer patients, which, unless treated, may lead to drug discontinuation and treatment failure. Some probiotics such as Lactobacillus, Bifidobacterium, and Saccharomyces species have been gaining clinical attention in alleviating chemotherapy-induced adverse events including diarrhea. This comprehensive review provides an overview and discusses preventive approaches of probiotics with respect to CID in several types of cancers. The potential mechanisms of probiotics may comprise regulation of intestinal microbiota, modulation of immune functions, or reduction of proinflammatory cytokines. The efficacy and safety precautions of probiotics in immunocompromised cancer patients are discussed. The non-pharmacological strategy using probiotics could reduce the use of anti-diarrheal or antibiotic agents. Some individuals experienced shorter length of hospital stay, better gastrointestinal function, and reduced incidence of chemotherapy dose reduction after probiotic administration. Nonetheless, some studies failed to report the benefits of probiotics in certain patients. This review also highlights preventive protocols and therapeutic implications by considering the potential influencing factors, particularly types of probiotic strains, dosages of probiotics, duration of their administration, patients' tolerability, and variations in probiotic effects over the cancer stages.

After morning, phew! A knowledge, attitudes, and practices survey related to emergency oral contraception in Thai pharmacists.

INTRODUCTION: Pharmacists' knowledge and attitude toward Emergency Oral Contraception (EOC) can affect users' access to EOCs, especially where EOCs are provided by pharmacists without the need for prescriptions. We conducted a Knowledge, Attitudes, and Practice (KAP) survey on Thai pharmacists to better understand KAP related to EOCs and the correlation among KAP components. METHODS: An in-depth interview, GoogleTrend search, and Pantip.com search were conducted. The findings, together with data from a previously published systematic review and meta-analysis, were used to develop KAP survey questions which were distributed online. Spearman's rank correlation coefficient and linear mixed model were used to investigate the correlation and association among KAP components. RESULTS: The in-depth interview with pharmacists showed that sex and unwanted pregnancy are very sensitive topics in Thailand. Sex and EOC education should be provided by parents and healthcare professionals at a young age. This agreed with opinions from Thai internet users that sex literacy was generally low and sex education was not provided adequately. From the total of 421 survey responses, Thai pharmacists had average knowledge, poor attitude, and average practice related to EOCs (median score = 51.02%, 21.81%, and 60.0%, respectively). The correlations between KAP in pharmacists were weak (ρ = 0.107-0.525, p < 0.02). Pharmacists who rated themselves as having higher scores in knowledge and attitude also rated themselves higher in the practice score. However, the total scores describing the knowledge of or attitude toward EOCs were not associated with EOC practice scores. CONCLUSIONS: In Thai pharmacists, self-rating KAP scores overestimated total KAP scores. The correlation among KAP components was weak. EOC knowledge and attitudes should be promoted, although this may not improve EOC practice in Thai pharmacists.

A systematic review and meta-analysis of the prevalence and association between levonorgestrel and ectopic pregnancy.

BACKGROUND: The use of levonorgestrel emergency oral contraceptives (EOCs) is one of the factors that may be associated with ectopic pregnancy. We aimed to investigate the incidence of ectopic pregnancy in EOC users and the association between EOCs and ectopic pregnancy. RESEARCH DESIGN AND METHODS: We searched for articles that provided the incidence of and the association between levonorgestrel EOCs and ectopic pregnancy in women of reproductive ages in CINAHL Complete, Medline, OpenDissertations, Scopus, Science Direct, and Thai Journal Online. The risk of bias was assessed by Risk Of Bias In Non-randomized Studies or Risk of Bias 2. A meta-analysis was conducted using the random-effects model. RESULTS: We retrieved 1839 nonredundant articles from the systematic search. The meta-analysis showed that the prevalence of ectopic pregnancy was not statistically different from zero (pooled prevalence estimate = 0.029%; 95%CI: -0.006, 0.065; N = 9; I2 = 0) and rare. In addition, levonorgestrel EOCs increased the risk of ectopic pregnancy (OR = 6.17; 95%CI: 3.78, 10.08; N = 5; I2 = 43%). CONCLUSIONS: Women with extrauterine or ectopic pregnancy had higher odds of using levonorgestrel emergency oral contraceptives than those with intrauterine pregnancy. However, the prevalence of ectopic pregnancy is rare.

A high-protein peptide-based enteral formula improves diarrhea in tube-fed patients: A prospective multicenter study.

BACKGROUND: Diarrhea is a common problem in tube-fed patients. The relevant guidelines suggest using a peptide-based enteral formula in patients with diarrhea; however, sufficient evidence to support this recommendation is currently lacking. AIM: This study aimed to evaluate the effects of a high-protein peptide-based formula on gastrointestinal intolerance, mainly focusing on diarrhea symptoms in patients who were intolerant to polymeric formula feeding. METHODS: This prospective, single-arm, open-label, multicenter study was conducted from March 2021 to March 2022 at two tertiary-care hospitals. Patients who presented with diarrhea during tube feeding with polymeric formula were assigned to receive a high-protein peptide-based formula for ≤7 days. Stool weight and frequency were monitored at baseline, on day 3, and on day 7 (or end of the study) as the primary outcomes. RESULTS: Twenty-eight tube-fed patients with diarrhea were recruited. After switching their feeding formula from polymeric to peptide based, significant improvements in stool frequency and stool weight were observed on day 3 and day 7 compared with the baseline (median [IQR] stool frequency: 5 (2), 2.5 (3.5), and 3 (3) times/day, respectively, p <0.001; median stool weight: 500 (370), 170 (285), and 275 (385) gram/day, respectively, p = 0.015). Stool consistency was assessed using the Bristol Stool Score and showed significant improvement with time. No serious adverse events were reported. CONCLUSION: A high-protein peptide-based enteral formula was effective in reducing stool weight and frequency in patients who experienced diarrhea during tube feeding with a polymeric formula.Trial registration: TCTR20210302006.

BRAF V600E Immunohistochemistry Predicts Prognosis of Patients with Cutaneous Melanoma in Thai population.

The BRAF V600E mutation in the Thai population has been identified in a considerable percentage of people with cutaneous melanoma. The objectives of this study were to determine the prevalence of this mutation in cutaneous melanomas, conduct a clinicopathological association analysis with the BRAF V600E mutation, and develop a treatment strategy for patients with this mutation that would take advantage of the medications currently available to treat them. Methods: Anti-BRAF V600E (clone VE1) immunohistochemistry was performed on 50 pathological samples of cutaneous melanoma after excluding the samples with a low amount of pathologic tissue, a lack of clinical data' and poor follow-up. BRAF V600E expression DNA sequencing was performed to confirm the results of several cases. Results: Anti-BRAF V600E antibody positivity was noted in 56% (28/50) of cutaneous melanoma cases. DNA sequencing results were consistent with immunohistochemistry results. In cutaneous melanoma, the BRAF V600E mutation was significantly associated with adverse prognosis of patients, including reduced overall survival and disease-free survival. Conclusions: An increased prevalence of the BRAF V600E mutation was determined in a collection of cutaneous melanomas in the Thai population, implying that BRAF-targeted therapy may be a promising strategy for patients with BRAF-mutated cutaneous melanoma. This study revealed an association between the clinicopathological aspects of cutaneous melanoma and overall survival, disease-free survival, and overall mortality. A treatment with anti-BRAF-targeted therapy, which incorporates the already available medications' is being researched and developed.

Nutritional Support with Omega-3 Fatty Acids in Burn Patients: A Systematic Review with Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: In burn patients, the profound effect of nutritional support on improved wound healing and a reduced rate of hospitalization and mortality has been documented. Fish oil as a primary source of omega-3 fatty acids in nutritional support may attenuate the inflammatory response and enhance immune function; however, unclear effects on the improvement of clinical outcomes in burn patients remain. METHODS: The systematic literature review was conducted by searching the electronic databases: Cochrane Library, PubMed, ScienceDirect, and Scopus to assess the randomized controlled trials of nutritional support with omega-3 fatty acids compared to control diets in patients that presented with burns from any causes. RESULTS: Seven trials were included in this meta-analysis. We found no significant differences in length of stay (LOS) (p = 0.59), mortality (p = 0.86), ventilation days (p = 0.16), gastrointestinal complications-e.g., constipation and diarrhea (p = 0.73)-or infectious complications-e.g., pneumonia and sepsis (p = 0.22)-between the omega-3-fatty-acid-receiving group and the control/other diets group. CONCLUSIONS: We did not find a benefit of omega-3 support in reducing the various complications, mortality and LOS in burn patients. Further studies are necessary to find the effect of nutritional support with omega-3 fatty acids over low-fat diets in this population.

Pharmacokinetic Outcomes of the Interactions of Antiretroviral Agents with Food and Supplements: A Systematic Review and Meta-Analysis.

Because pharmacokinetic changes in antiretroviral drugs (ARV), due to their concurrent administration with food or nutritional products, have become a clinical challenge, it is necessary to monitor the therapeutic efficacy of ARV in people living with the human immunodeficiency virus (PLWH). A systematic review and meta-analysis were conducted to clarify the pharmacokinetic outcomes of the interaction between supplements such as food, dietary supplements, and nutrients, and ARV. Twenty-four articles in both healthy subjects and PLWH were included in the qualitative analysis, of which five studies were included in the meta-analysis. Food−drug coadministration significantly increased the time to reach maximum concentration (tmax) (p < 0.00001) of ARV including abacavir, amprenavir, darunavir, emtricitabine, lamivudine, zidovudine, ritonavir, and tenofovir alafenamide. In addition, the increased maximum plasma concentration (Cmax) of ARV, such as darunavir, under fed conditions was observed. Area under the curve and terminal half-life were not significantly affected. Evaluating the pharmacokinetic aspects, it is vital to clinically investigate ARV and particular supplement interaction in PLWH. Educating patients about any potential interactions would be one of the effective recommendations during this HIV epidemic.

Alu repetitive sequence CpG methylation changes in burn scars.

Alu elements are retrotransposons related to epigenetic modifications. To date, the role of epigenetics in hypertrophic scars from burn remains unknown. Here, our aim was to examine the pathophysiology of hypertrophic scars from an epigenetic perspective. For that, we performed a cross-sectional analytical study using tissue and blood samples from burned and healthy patients (n = 23 each) to detect Alu methylation levels and patterns. The results of the combined bisulfite restriction analysis technique were categorized into four groups based on the methylation status at the CpG dinucleotides from the 5' to the 3' ends of the Alu sequence: hypermethylated (mCmC), hypomethylated (uCuC), and partially methylated (uCmC and mCuC). Alu methylation levels were significantly lower in hypertrophic scar tissues than in normal skin (29.37 ± 2.49% vs. 35.56 ± 3.18%, p = 0.0002). In contrast, the levels were significantly higher in white blood cells from blood samples of burned patients than in those of control blood samples (26.92 ± 4.04% vs. 24.58 ± 3.34%, p = 0.0278). Alu total methylation (mC) and the uCmC pattern were significantly lower, whereas uCuC was significantly higher, in hypertrophic scar tissues than in normal skin (p < 0.0001). Receiver operating characteristic analysis indicated that the uCmC and uCuC patterns are useful as hypertrophic scar DNA methylation markers after burn, with 91.30% sensitivity and 96.23% specificity and 100% sensitivity and 94.23% specificity, respectively. Our findings suggest that epigenetic modifications play a major role in hypertrophic scar pathogenesis, and may be the starting point for developing a novel technique for burn scar treatment.

Deterioration of Nutritional Status and Its Negative Association with Depression Among Older HIV-Infected Asian Population: A Four-Year Longitudinal Study.

There is limited evidence about the long-term changes in nutritional status among the elderly people living with human immunodeficiency virus (PLWH). We aimed to investigate the changes in nutritional status and related factors over 4 years in the elderly PLWH. The longitudinal study was conducted prospectively among 250 PLWH, 50 years of age and older, receiving antiretroviral therapy (ART). The Mini Nutritional Assessment (MNA) and Thai Depression Scale (TDS) to assess nutritional status and depression, respectively, were performed at the outpatient clinic both at baseline and 4-year follow-up. Majority were male (60.8%) with median age of 58 years. The median CD4 was 612.5 cells/mm3 and 98% had HIV RNA <50 copies/mL. Median duration of ART was 20 years. Median body mass index was 23.1 kg/m2. The most common ART were rilpivirine (45.2%) and dolutegravir (18.8%). Fifty-one patients (20.4%) deteriorated in nutritional status and mean MNA scores declined (25.8 vs. 24.8, p < .001) at follow-up period. In multivariate analysis, high TDS scores (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.17-1.52), polypharmacy (OR, 1.35; 95% CI, 1.10-1.65), and high-density lipoprotein cholesterol (HDL-C) levels (OR, 1.04; 95% CI, 1.01-1.07) were associated factors of deterioration in nutritional status. In this 4-year longitudinal follow-up, 20% of the aging PLWH have deterioration of nutritional status. High TDS scores (depression), polypharmacy, and high HDL-C were significantly associated with declining nutritional status. Our findings highlight the importance of screening and monitoring nutritional and depression status in routine HIV treatment and care for geriatric HIV-infected population.

Nutritional assessment in the HIV-infected older population receiving antiretroviral therapy.

Malnutrition is a pronounced public health issue which often seems underestimated in the older people living with HIV (PLWH) virus infection. PLWH are highly vulnerable to nutritional problems resulting from agingrelated deterioration, disease itself, and adverse effects of antiretroviral therapy (ART). The comprehensive nutritional assessments are necessary to perform routinely in this population to monitor and provide appropriate interventions to reduce comorbid conditions. In this review, we focus on the untoward impacts of malnutrition and nutritional assessments on the morbidity and mortality in the older PLWH. Some predictive factors of nutritional status in this group of patients are discussed. We propose the important components for nutrition assessment tool for older PLWH on ART. Highlighted issue is the need for developing uniform standardized tools for the early diagnosis of malnutrition in this population. Applications of the nutritional assessments, proper nutritional interventions, and regular monitoring of nutritional status in older PLWH liv-ing in every clinical setting may help the patients get better well-being.

Antiretroviral Therapy-Associated Metabolic Complications: Review of the Recent Studies.

The extensive utilization of antiretroviral therapy (ART) has successfully improved human immunodeficiency virus (HIV)-associated complications. The incidence of opportunistic infections is decreased by the viral load suppression and the CD4 count promotion. However, metabolic complications, commonly bone demineralization, lipodystrophy, and lactic acidosis, are arising following the adaptation of long-term ART. The events are not drug-specific, but the severity and incidence individually vary depending upon classes of drugs. Such concerning occurrences may lead to discontinuation of current therapy or switching to another regimen with fewer adverse effects. The purpose of this review is to demonstrate the common metabolic abnormalities associated with each class of widely used ART in people living with HIV (PLHIV). Electronic databases such as PubMed, ScienceDirect, Scopus, Google Scholar, SciFinder, and Web of Science were used for the literature search. A better understanding of ART-associated metabolic adverse effects is helpful in various clinical settings so that therapists may optimize treatments in this population.

The effects of Bombyx mori silk strain and extraction time on the molecular and biological characteristics of sericin.

Sericin was extracted from three strains of Thai Bombyx mori silk cocoons (white shell Chul1/1, greenish shell Chul3/2, and yellow shell Chul4/2) by a high-pressure and high-temperature technique. The characteristics of sericin extracted from different fractions (15, 45, and 60 min extraction process) were compared. No differences in amino acid composition were observed among the three fractions. For all silk strains, sericin extracted from a 15-min process presented the highest molecular weight. The biological potential of the different sericin samples as a bioadditive for 3T3 fibroblast cells was assessed. When comparing sericin extracted from three silk strains, sericin fractions extracted from Chul4/2 improved cell proliferation, while sericin from Chul 1/1 activated Type I collagen production to the highest extent. This study allows the natural variability of sericin obtained from different sources and extraction conditions to be addressed and provides clues for the selection of sericin sources.

Improvement of Physical and Wound Adhesion Properties of Silk Sericin and Polyvinyl Alcohol Dressing Using Glycerin.

OBJECTIVE: This study aimed to use glycerin to improve physical and wound adhesion properties of a wound dressing made of silk sericin and polyvinyl alcohol (PVA). DESIGN: Glycerin of a natural-derived plasticizer was used to modify the properties of silk sericin/PVA scaffolds. Various concentrations of glycerin were mixed with silk sericin and PVA and then fabricated into the scaffolds by a freeze-drying technique. The control study was performed to examine the properties of the silk sericin/PVA scaffolds with and without glycerin. MAIN OUTCOME MEASURES: Physical, mechanical, wound adhesion properties, the release profile of silk sericin, and in vivo safety of the silk sericin/PVA scaffolds with and without glycerin were investigated. MAIN RESULTS: The silk sericin/PVA scaffolds with glycerin exhibited more homogenous structure, less compressive modulus, higher Young modulus and elongation percentage, and a higher degree of crosslinking compared with the scaffold without glycerin. The silk sericin/PVA scaffold with 2% wt/vol glycerin showed more controlled release of silk sericin than the other scaffolds. The sustained release of silk sericin from the scaffold with glycerin would be advantageous for long-term healing of wounds. The silk sericin/PVA scaffold with 2% (wt/vol) glycerin was less adhesive to the wound compared with the scaffold without glycerin. Furthermore, the implantation of silk sericin/PVA scaffolds with 2% (wt/vol) glycerin did not cause any irritation to the tissue. CONCLUSION: The silk sericin/PVA scaffolds with glycerin were introduced as a biocompatible, more flexible, and less adhesive wound dressing than the scaffold without glycerin.

Clinical potential of a silk sericin-releasing bioactive wound dressing for the treatment of split-thickness skin graft donor sites.

PURPOSE: An ethyl alcohol-precipitated silk sericin/PVA scaffold that controlled the release of silk sericin was previously developed and applied for the treatment of full-thickness wounds in rats and demonstrated efficient healing. In this study, we aimed to further evaluate the clinical potential of this scaffold, hereafter called "silk sericin-releasing wound dressing", for the treatment of split-thickness skin graft donor sites by comparison with the clinically available wound dressing known as "Bactigras®". METHODS: In vitro characterization and in vivo evaluation for safety of the wound dressings were performed. A clinical trial of the wound dressings was conducted according to standard protocols. RESULTS: The sericin released from the wound dressing was not toxic to HaCat human keratinocytes. A peel test indicated that the silk sericin-releasing wound dressing was less adhesive than Bactigras®, potentially reducing trauma and the risk of repeated injury upon removal. There was no evidence of skin irritation upon treatment with either wound dressing. When tested in patients with split-thickness skin graft donor sites, the wounds treated with the silk sericin-releasing wound dressing exhibited complete healing at 12 ± 5.0 days, whereas those treated with Bactigras® were completely healed at 14 ± 5.2 days (p = 1.99 × 10(-4)). In addition, treatment with the silk sericin-releasing wound dressing significantly reduced pain compared with Bactigras® particularly during the first 4 postoperative days (p = 2.70 × 10(-5) on day 1). CONCLUSION: We introduce this novel silk sericin-releasing wound dressing as an alternative treatment for split-thickness skin graft donor sites.

Preliminary characterization of genipin-cross-linked silk sericin/poly(vinyl alcohol) films as two-dimensional wound dressings for the healing of superficial wounds.

The genipin-cross-linked silk sericin/poly(vinyl alcohol) (PVA) films were developed aiming to be applied as two-dimensional wound dressings for the treatment of superficial wounds. The effects of genipin cross-linking concentration on the physical and biological properties of the films were investigated. The genipin-cross-linked silk sericin/PVA films showed the increased surface density, tensile strength, and percentage of elongation, but decreased percentage of light transmission, water vapor transmission rate, and water swelling, compared to the non-cross-linked films. This explained that the cross-linking bonds between genipin and silk sericin would reduce the mobility of molecular chains within the films, resulting in the more rigid molecular structure. Silk sericin was released from the genipin-cross-linked films in a sustained manner. In addition, either L929 mouse fibroblast or HaCat keratinocyte cells showed high percentage of viability when cultured on the silk sericin/PVA films cross-linked with 0.075 and 0.1% w/v genipin. The in vivo safety test performed according to ISO 10993-6 confirmed that the genipin-cross-linked silk sericin/PVA films were safe for the medical usages. The efficacy of the films for the treatment of superficial skin wounds will be further investigated in vivo and clinically. The genipin-cross-linked silk sericin/PVA films would be promising choices of two-dimensional wound dressings for the treatment of superficial wounds.

Sericin cream reduces pruritus in hemodialysis patients: a randomized, double-blind, placebo-controlled experimental study.

BACKGROUND: Uremic pruritus (UP) is a significant complication in ESRD patients and substantially impairs their quality of life. UP is considered to be a skin manifestation of chronic inflammation. Because sericin can suppress the release of pro-inflammatory cytokines, the purpose of this study was to investigate the short-term safety and efficacy of sericin cream for treating UP in hemodialysis patients. METHODS: This study used a double-blind design to investigate the effects of random topical administration of sericin cream and cream base (placebo) on either the right or left extremities of hemodialysis patients for 6 weeks. Skin hydration, irritation and pigmentation were evaluated every 2 weeks using Skin Diagnostic SD27. The visual analog scale for itching was also evaluated every 2 weeks, and the Kidney Disease Quality of Life Short Form was performed on the day of each patient's enrollment and after 6 weeks of treatment. RESULTS: Fifty dialysis patients were enrolled, 47 of which completed the study. The hydration of the skin of the patients' extremities increased significantly after administration of sericin cream; significant differences were found between sericin treatment and control after 6 weeks of treatment (p = 0.041 for arms and p = 0.022 for legs, respectively). Moreover, a significant difference was also found in skin irritation between the two treatments (p = 0.013 for arms and p = 0.027 for legs, respectively). At the end of the study, the skin pigmentation level was significantly reduced on both the arms (p = 0.032) and legs (p = 0.021) of the sericin-treated side compared with the side treated with cream base. The mean itching score decreased significantly from moderate to severe at the time of enrollment to mild pruritus after 6 weeks of treatment (p = 0.002). A better quality of life was found in all domains tested although statistically significant differences before and after treatment was found only in the patients' pain scores, the effect of kidney disease on daily life, sleep quality and symptoms or problems related to kidney disease. CONCLUSIONS: We conclude that sericin cream has a high potential for reducing UP in hemodialysis patients.The trial registration number of this study is ISRCTN16019033; its public title is "sericin cream reduces pruritus in hemodialysis patients".

Potential applications of silk sericin, a natural protein from textile industry by-products.

Silk is composed of two major proteins, fibroin (fibrous protein) and sericin (globular, gumming protein). Fibroin has been used in textile manufacturing and for several biomaterial applications, whereas sericin is considered a waste material in the textile industry. Sericin has recently been found to activate the proliferation of several cell-lines and has also shown various biological activities. Sericin can form a gel by itself; however, after mixing with other polymers and cross-linking it can form a film or a scaffold with good characteristics that can be used in the cosmetic and pharmaceutical industries. Sericin is proven to cause no immunological responses, which has resulted in a more acceptable material for biological applications.

The effect of sterilization methods on the physical properties of silk sericin scaffolds.

Protein-based biomaterials respond differently to sterilization methods. Since protein is a complex structure, heat, or irradiation may result in the loss of its physical or biological properties. Recent investigations have shown that sericin, a degumming silk protein, can be successfully formed into a 3-D scaffolds after mixing with other polymers which can be applied in skin tissue engineering. The objective of this study was to investigate the effectiveness of ethanol, ethylene oxide (EtO) and gamma irradiation on the sterilization of sericin scaffolds. The influence of these sterilization methods on the physical properties such as pore size, scaffold dimensions, swelling and mechanical properties, as well as the amount of sericin released from sericin/polyvinyl alcohol/glycerin scaffolds, were also investigated. Ethanol treatment was ineffective for sericin scaffold sterilization whereas gamma irradiation was the most effective technique for scaffold sterilization. Moreover, ethanol also caused significant changes in pore size resulting from shrinkage of the scaffold. Gamma-irradiated samples exhibited the highest swelling property, but they also lost the greatest amount of weight after immersion for 24 h compared with scaffolds obtained from other sterilization methods. The results of the maximum stress test and Young's modulus showed that gamma-irradiated and ethanol-treated scaffolds are more flexible than the EtO-treated and untreated scaffolds. The amount of sericin released, which was related to its collagen promoting effect, was highest from the gamma-irradiated scaffold. The results of this study indicate that gamma irradiation should have the greatest potential for sterilizing sericin scaffolds for skin tissue engineering.