SYNTHESIS OF BIOPOLYMER–CARBONATE APATITE AS BONE SCAFFOLD BY BIOMIMETIC METHOD

• Main Author: HALIM DAULAY (NIM : 33710001), ABDUL
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20660
• Institution: Institut Teknologi Bandung

The needs of biomaterial poducts, particularly related to the repair/replacement of bone loss/defect, increases every year. The use of grafting methods where source of tissue derived from itself (autograft) or donor (allograft) have some limitations such as the availability of donors, antigenicity issue, post-surgery pain and trauma, and the high cost. To overcome the problems, many studies in the field of tissue engineering is conducted to develop the proper synthetic substitute materials for bone or tissue regeneration, one of which is biomimetic method, which is a method inspired by natural processes and designs. <br /> At this study, biopolymers and carbonate apatite is synthesized by biomimetic method for the application of bone scaffold. The biopolymers used are alginate and chitosan which are extracted from brown algae and shell of crustaceans respectively. The biopolymers were chosen because of their excellent biocompatibility and biodegradability when applied in biological system and their abundant availability in nature. Carbonate apatite is inorganic constituent of bone apatite which has high osteoconductivity and resorption rate. Carbonate apatite was prepared by sol gel and followed by co-precipitation method and maintained in an amorphous structure. The biocomposite material is produced by blending alginate, chitosan, and carbonate apatite in certain variations of composition. To produce pores on scaffold, the methods used are eggshell membrane template, electrospinning, and freeze drying. By the methods, pores obtained will resemble the micro environment of cells and can enhance the interface interaction. Several characterization methods used in this study are Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infra Red (FTIR) Spectroscopy, Brunauer-Emmet-Teller (BET) Characterization, Tensile and Compressive Strength Test, and viability test of mesenchymal stem cells by MTT assay. <br /> There are some conclusions that can be obtained from the research conducted, (i) alginate-chitosan/carbonate apatite based scaffolds with open and interconnected pores have been synthesized by eggshell membrane template, electrospinning, and freeze drying methods. The diameter size of scaffold A and B are 1 – 7 &#956;m and 0,1 – 1 &#956;m respectively with spaces among fibers can be considered as pores with pore size of about 1 – 25 &#956;m and 1 – 10 &#956;m respectively. While the scaffold C has a pore size of 50 – 300 &#956;m. EDS-mapping characterizations showed that scaffolds consist of carbonate apatite which is distributed evenly. The existence of carbonate apatite in the scaffolds is shown by FTIR results which are characterized by the presence of phosphate and carbonate functional groups, (ii) The tensile strength of scaffold A and B are 5,17 – 6,74 MPa and 0,90 – 2,76 MPa respectively while compressive strength of scaffold C is 2,33 – 2,39 MPa which are still in the range of tensile and compressive strength value of cancellous bone, i.e. 0,1 – 20 MPa and 2 – 12 MPa consecutively, (iii) The viability test of Mesenchymal stem cells exposed to scaffold extract solutions by MTT (3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay method showed that the extract solutions of scaffold A, B, dan C which was exposed to Mesenchymal stem cells at concentrations of 0.01 – 100% affect the viability of cells. Scaffold B is the most inhibiting cells growth, then followed by scaffold A and C, and (iv) If viewed from several aspects such as processing methods, pore sizes, tensile or compressive strength, and the viability of Mesenchymal stem cells affected by scaffold extract solutions exposure, scaffold C has the most optimum characteristics, and then followed by scaffold A and B. <br /> There are some suggestions that can be proposed related to the research that has been conducted, further in vitro and in vivo tests need to be done to complete the biological evaluation, to determine the properties associated with the interaction between scaffolds and animal testing, before applied clinically in human.