Fabrication of Helix aspersa Extract Loaded Gradient Scaffold with an Integrated Architecture for Osteochondral Tissue Regeneration: Morphology, Structure, and In Vitro Bioactivity.

Regeneration of osteochondral tissue with its layered complex structure and limited self-repair capacity has come into prominence as an application area for biomaterial design. Thus, literature studies have aimed to design multilayered scaffolds using natural polymers to mimic its unique structure. In this study, fabricated scaffolds are composed of transition layers both chemically and morphologically to mimic the gradient structure of osteochondral tissue. The aim of this study is to produce gradient chitosan (CHI) scaffolds with bioactive snail (Helix aspersa) mucus (M) and slime (S) extract and investigate the structures regarding their physicochemical, mechanical, and morphological characteristics as well as in vitro cytocompatibility and bioactivity. Gradient scaffolds (CHI-M and CHI-S) were fabricated via a layer-by-layer freezing and lyophilization technique. Highly porous and continuous 3D structures were obtained and observed with SEM analysis. In addition, scaffolds were physically characterized with water uptake test, micro-CT, mechanical analysis (compression tests), and XRD analysis. In vitro bioactivity of scaffolds was investigated by co-culturing Saos-2 and SW1353 cells on each compartment of gradient scaffolds. Osteogenic activity of Saos-2 cells on extract loaded gradient scaffolds was investigated in terms of ALP secretion, osteocalcin (OC) production, and biomineralization. Chondrogenic bioactivity of SW1353 cells was investigated regarding COMP and GAG production and observed with Alcian Blue staining. Both mucus and slime incorporation in the chitosan matrix increased the osteogenic differentiation of Saos-2 and SW1353 cells in comparison to the pristine matrix. In addition, histological and immunohistological staining was performed to investigate ECM formation on gradient scaffolds. Both characterization and in vitro bioactivity results indicated that CHI-M and CHI-S scaffolds show potential for osteochondral tissue regeneration, mimicking the structure as well as enhancing physical characteristics and bioactivity.

Bioactive snail mucus-slime extract loaded chitosan scaffolds for hard tissue regeneration: the effect of mucoadhesive and antibacterial extracts on physical characteristics and bioactivity of chitosan matrix.

Biobased extracts comprise various bioactive components and they are widely used in tissue engineering applications to increase bioactivity as well as physical characteristics of biomaterials. Among animal sources, garden snailHelix aspersahas come into prominence with its antibacterial and regenerative extracts and show potential in tissue regeneration. Thus, in this study, bioactiveH. aspersaextracts (slime, mucus) were loaded in chitosan (CHI) matrix to fabricate porous scaffolds for hard tissue regeneration. Physical, chemical properties, antimicrobial activity was determined as well asin vitrobioactivity for bone and cartilage regeneration. Mucus and slime incorporation enhanced mechanical properties and biodegradation rate of CHI matrix. Scanning electron microscopy images showed that the average pore size of the scaffolds decreased with higher extract content. Mucus and slime extracts showed antimicrobial effect on two bacterial strains.In vitrocytotoxicity, osteogenic and chondrogenic activity of the scaffolds were evaluated with Saos-2 and SW1353 cell lines in terms of Alkaline phosphatase activity, biomineralization, GAG, COMP and hydroxyproline content. Cell viability results showed that extracts had a proliferative effect on Saos-2 and SW1353 cells when compared to the control group. Mucus and slime extract loading increased osteogenic and chondrogenic activity. Thus, the bioactive extract loaded CHI scaffolds showed potential for bone and cartilage regeneration with enhanced physical properties andin vitrobioactivity.

Protective effect of alpha lipoic acid on 4-vinylcyclohexene diepoxide induced primary ovarian failure in female rats.

OBJECTIVE: The effects of alpha lipoic acid (ALA) and its possible mechanisms in treating Primary ovarian failure (POF) model was studied with 4 vinylcyclohexene diepoxide (VCD). MATERIAL AND METHODS: Rats were divided into 4 groups (n = 7) as Control, VCD, VCD + ALA and ALA. POF model was induced by applying VCD intraperitoneally and ALA was administered by oral gavage as 100 mg/day to the VCD + ALA and ALA groups. RESULTS: At the end of 42 days, ovarian and uterine tissues were received. The number of primordial and primary follicles were increased and corpus luteum and cystic follicles were decreased in ovarian tissues in VCD + ALA group compared to VCD group. Caspase-3 immunoreactivity in follicular cells was decreased in VCD + ALA group compared to VCD group. eNOS immunoreactivity and eNOS levels were decreased in VCD group and increased in VCD + ALA group while iNOS immunoreactivity and iNOS levels were increased in VCD group, decreased in VCD + ALA group in ovary and uterine tissue. Plasma FSH and LH hormone levels were increased in the VCD but decreased in VCD + ALA group. Estradiol level decreased in the VCD group compared to the other groups. The MDA values were significantly increased in the VCD + ALA group compared to VCD group. In addition, the levels of GSH values were decreased in VCD + ALA group compared to VCD group. CONCLUSION: Alpha lipoic acid treatment of rats with VCD-induced POF had a beneficial effect on reducing ovarian damage by improving histological, immunohistochemical, hormone level and oxidative stress markers. Our results show that ALA is an effective treatment of VCD-induced POF rats.