Saudi Cultural Missions Theses & Dissertations
Permanent URI for this communityhttps://drepo.sdl.edu.sa/handle/20.500.14154/10
Browse
3 results
Search Results
Item Restricted Polydopamine-ECM Coated Titanium to Promote Cementogenesis on Dental Implants(Harvard University, 2025) Alamri, Osamah; Traverso, GiovanniTitanium dental implants integrate directly with the surrounding bone, a phenomenon known as osseointegration. Unlike natural teeth, which are supported by periodontal ligaments (PDL), osseointegrated implants have weaker mechanical barriers against bacterial infiltration, heightened inflammation, reduced blood flow, and limited proprioception. Current methods to regenerate peri-implant ligaments involve costly, invasive, and time-intensive procedures. Polydopamine (PDA) is a biocompatible polymer known for its excellent adhesive properties. Periodontal ligament fibroblasts (PDLFs) play a pivotal role in periodontal tissue maintenance. Recent evidence suggests fibroblasts can induce a cementogenic phenotype by altering titanium surface topography and depositing cementum-like tissue. This study investigates PDA's efficacy in immobilizing ECM produced by PDLFs on titanium, hypothesizing enhanced cementogenesis on PDA-coated titanium surfaces. We assessed ECM immobilization efficiency, optimized decellularization protocols to retain ECM, and evaluated PDLF differentiation into a cementogenic phenotype. PDLFs cultured on PDA-coated titanium underwent decellularization after 10 days, followed by recellularization for 14 days. Cell interactions and gene expression were assessed using immunofluorescence microscopy, scanning electron microscopy (SEM), and RT-qPCR. Results demonstrated increased cell numbers on PDA-coated surfaces without affecting attachment or proliferation. Decellularization effectively removed cellular material, preserving key ECM proteins like Collagen I and CEMP-1. Gene expression analysis revealed significant upregulation of cementogenic markers (CP23, CAP, CEMP1, BSP) and downregulation of osteogenic markers (ALP, SOST), especially prominent on PDA-ECM surfaces. Our findings support that PDA-ECM-coated titanium surfaces promote cementogenic differentiation of PDLFs, potentially enabling peri-implant cementum-like tissue formation and periodontal ligament regeneration.17 0Item Restricted Decellularized tissue-derived scaffolds in bone tissue engineering(King’s College London, 2021-08) Alokla, Mohammad; Deb, SanjuktaBone tissue engineering has received significant attention due to its enormous potential in treating critical-sized bone defects and related diseases. The shortage of suitable autograft and allograft materials for augmenting bone healing has accelerated research in developing clinically viable tissue engineered bone constructs. Optimal scaffold for bone tissue engineering should be osteoconductive, osteoinductive, biodegradable, sterilizable, provide adequate mechanical support bioactivity and biocompatible, hence traditional materials such as polymers, polymer-composites, ceramics and metals have been widely researched as scaffolds, however clinical applications have been limited due to different limitations. A three-dimensional scaffold that is able to replicate the in vivo microenvironment is essential for bone tissue engineering and the use of decellularized scaffolds is an approach that is generating interest especially the role of cellulose from plant source. This review discusses the anatomy of bone with a focus on bone physiology, bone defects and existing treatments, bone tissue engineering and then summarizes the status of the use of decellularized plant and animal tissues, different types of decellularization processes and clinical challenges.14 0Item Restricted A STUDY OF THE EFFECT OF PREPARATION PARAMETERS ON THE MECHANICAL PROPERTIES OF FREEZE-DRIED GELATIN-ELASTIN-HYALURONATE SCAFFOLDS(Marquette University, 2024-05) Qamash, Mansour; Tayebi, LobatThis thesis is dedicated to a detailed study of changes in the properties of Gelatin-Elastin Hyaluronate (GEH) tissue engineering scaffold resulting from changes in preparation parameters. More specifically, utilizing a combination of foaming and freeze-drying techniques, this research investigates the effects of different parameters, including agitation speed, duration time, and chilling temperature on the scaffold’s structural integrity, porosity, and mechanical properties. The methodology involves a carefully calibrated process in which the scaffold matrix is initially prepared by incorporating 8% gelatin, 2% elastin, and 0.5% hyaluronate (w/v) into a homogenous aqueous solution, followed by controlled agitation and subsequent freezing at designated temperatures. The freeze-drying stage solidifies the foam structure, creating a porous matrix essential for cell growth and nutrient delivery. The findings reveal that porosity and mechanical properties, such as compressive Young’s modulus, of scaffolds are significantly influenced by fabrication parameters, with higher agitation speeds and longer duration times leading to increased porosity and decreased modulus. Moreover, the degradation rates of the scaffolds processed at both −20 and −80°C were found to be comparable, indicating a similar level of preservation in physiological conditions. Morphological analyses, including laser microscopy and scanning electron microscopy (SEM), indicated optimal pore sizes (100–300 µm) that promote effective cell interaction and tissue regeneration, confirming the successful application of the freeze-drying and foaming methods in creating highly interconnected porous structures. Based on the findings, a decrease in chilling temperature correlates with a slight increase in pore size within the scaffold matrix. The methodical fabrication process developed in this study emphasizes the control of agitation speed and duration to modulate scaffold porosity, which is an essential characteristic for cellular infiltration and vascularization in tissue engineering. The research outcomes demonstrate that scaffold properties can be finely adjusted through the preparation process, offering the potential to match the structural needs of specific tissue engineering applications. The thesis contributes significant advancements in scaffold design, providing a robust framework for the development of tissue scaffolds with controlled porosity and improved mechanical properties. By understanding and harnessing the effects of fabrication parameters, this research offers a pathway to design scaffolds that more accurately replicate the extracellular matrix, promoting enhanced tissue repair and regeneration.21 0