Sarcotragus Foetidus Süngerinin Sert ve Yumuşak Doku Mühendisliği Uygulamaları İçin Fabrikasyonu ve İn Vitro Karakterizasyonu

Abstract

In this doctoral study, multifunctional systems were developed using natural spongin structures derived from the marine sponge Sarcotragus foetidus, a member of the class Demospongiae, for potential biomedical applications in both tissue engineering and glioblastoma multiforme (GBM) therapy. In the first part of the study, it was hypothesized that scaffolds derived from Sarcotragus foetidus, due to their spongin content, would support osteogenic differentiation, and that this effect would be further enhanced by boron-doped hydroxyapatite (B-HAp) coating through the stimulation of additional differentiation pathways. Within this hypothesis, three-dimensional (3D) spongin-based scaffolds were initially isolated from the marine sponge Sarcotragus foetidus. The scaffolds were then coated with hydroxyapatite and boron-doped hydroxyapatite to improve their osteoinductive properties. In vitro studies using MC3T3-E1 preosteoblast cells demonstrated that the scaffolds maintained cell viability and promoted osteogenic differentiation. Particularly in the B-HAp coatedgroup, expression levels of Col1a1 and Ocn genes increased approximately 2.5-fold. Histological examinations confirmed enhanced mineralization, while antibacterial tests showed that especially B-HAp coated scaffolds exhibited pronounced bacteriostatic activity against both Gram-positive and Gram-negative bacteria. In the second part of the study, collagen was successfully isolated from Sarcotragus foetidus with high yield and purity. The isolated collagen showed a protein yield of approximately 12%, a total protein content of ~350 mg/g dry weight, and a hydroxyproline content of ~9%. Structural and chemical characterization, conducted through various analytical methods, revealed that the collagen retained its triple helical structure and showed high similarity to Type I collagen, indicating a high-quality material. This collagen was crosslinked via EDC/NHS to form a hydrogel and provided a biocompatible matrix suitable for soft tissue engineering applications. In the final part of the study, PBAT (poly(butylene adipate-co-terephthalate)) nanoparticles loaded with gallic acid (GA) were developed for GBM therapy and coated with Opuntia ficus indica mucilage (ONM) to enable controlled drug release. The optimized formulations yielded nanoparticles with an average size of 190 ± 69 nm and approximately 87% encapsulation efficiency. These nanoparticles were successfully integrated into Sarcotragus foetidus sponge-based scaffolds. In vitro analyses using T98G glioblastoma cells revealed that GA-loaded and ONM-coated nanoparticles exhibited significant cytotoxic and apoptotic effects, increasing caspase-3 gene expression while significantly suppressing tumor-associated genes c-Myc and β-catenin. In conclusion, this study demonstrated that the biological structures derived from Sarcotragus foetidus can be effectively utilized in multifunctional biomedical applications. These natural materials were successfully transformed into both scaffold systems supporting tissue regeneration and efficient carriers providing controlled drug release.