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Since administration of androgens has been considered appreciable in hair follicle growth and wound healing, therefore the main objective in this study is evaluation the effect of sheep testis extract on improvement and growth of hair follicle and regeneration of injured Wistar rat skin. In this experimental study, rats were randomly divided into 7 groups, control (negative control), sham (treatment with physiologic serum), experimental group 1 (treatment with 100% sheep testis extract), experimental group 2 (treatment with 75% extract), experimental group 3 (treatment with 50% extract), positive control 1 (treatment with honey) for evaluation of wound healing and positive control 2 (treatment with Minoxidil) for evaluation of hair follicle growth. Then, rats were killed after and removed approximate wound skin, fixed in 10% formalin, kept in paraffin block. In addition, it was prepared serial section with 6 µm thickness and performed hematoxylin eosin staining. Then, epidermal thickness, the number of fibroblast, basal cells, inflammatory cells, vessel bud and hair follicle were assessed. Statistical analysis was performed by one way ANOVA, Tukey test at p ˃0.05. The results showed that wound healing process, hair follicle formation, the re-epithelialization, angiogenesis, the number of basal cell, fibroblasts, and the number of follicles was significantly improved in the experimental group 1, 2, rather than control group (p ˃0.05).  Results of this study demonstrated that the sheep testis extract induced improvement in regeneration process, wound healing and hair follicle growth in rats which can be suggested as an appreciable candidate due to rich source of androgen and growth factors in clinical wound healing studies.

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Basic fibroblast growth factor (bFGF), also known as FGF-2, is a crucial member of the fibroblast growth factor family, involved in a variety of biological functions including cellular proliferation, wound healing, angiogenesis, intercellular signalling, and cell differentiation, In contemporary stem cell research, serum-free media enriched with various additives and growth factors are employed, and among these, bFGF being particularly significant. Despite its extensive potential applications, the clinical utilization of bFGF is limited due to its instability, especially in aqueous environment. Therefore, a thorough investigation of the protein's structural integrity and stability is essential. This study focuses on the expression, purification, and characterization of bFGF for structural and stability analysis through biophysical methods. Intrinsic fluorescence measurement indicated a structural alteration surrounding the tryptophan residue, while circular dichroism (CD) analysis showed a decrease in the protein’s secondary structure. The differential scanning calorimetry (DSC) used for stability analysis. Furthermore, the study aims to evaluate the biological activity of the protein in cellular context. For this purpose, gold nanoparticles were synthesized. The results from the Cell Migration Assay indicated that the proliferation of HT29 cells was enhanced following treatment with bFGF in conjunction with gold nanoparticles. Also, a MTT assay was conducted.