A Study on Biomineralization Behavior of N‐Methylene Phosphochitosan Scaffolds

Abstract

Biomimetic growth of calcium phosphate over natural polymer may be an effective approach to constituting an organic/inorganic composite scaffold for bone tissue engineering. In this work, N-methylene phosphochitosan (NMPCS) was prepared via formaldehyde addition and condensation with phosphoric acid in a step that allowed homogeneous modification without obvious deterioration in chitosan (CS) properties. The NMPCS obtained was characterized by using FT-IR and elemental analysis. The macroporous scaffolds were fabricated through a freeze-drying technique. A comparative study on NMPCS and CS scaffold biomimetic mineralization was carried out in different media, i.e, a simulated body fluid (SBF) or alternative CaCl(2) and Na(2)HPO(4) solutions respectively. Apatite formation within NMPCS and CS scaffolds was identified with FT-IR, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffractometery (XRD). The results revealed alternate soaking of the scaffolds in CaCl(2) and Na(2)HPO(4) solutions was better than soaking in SBF solution alone in relation to apatite deposition on the scaffold pore walls. Biomineralization provides an approach to improve nature derived materials, e.g., chitosan derivative NMPCS properties e.g., compressive modulus, etc. SEM image of a NMPCS/apatite composite scaffold.

Bone tissue engineering with premineralized silk scaffolds

“…The preparation of a range of bone-like materials has been reported [6,29,[42][43][44][45][46][47][48][49]. Natural bone is a biocomposite in which inorganic apatite crystals are deposited on collagen fibers woven into a three dimensional structure.…”

“…HAP-binding proteins have definitive HAP-binding sites based on acid side chains on amino acids. Proteins containing aspartic acid-rich sequences interact with crystals of calcium salt in a specific manner [50,51], and poly-glutamic acid sequences or poly-aspartic acid sequences are present in HAP-binding proteins [49]. From a comparison of Fig.…”

“…HAP consists of Ca 2+ ions surrounded by both PO 4 2− and OH − ions. Once the apatite nuclei form, spontaneous growth occurs by addition of calcium and phosphate ions from the surrounding medium during soaking in CaCl 2 and Na 2 HPO 4 to trigger the deposition of apatite [49,52].…”

Adhesion, Proliferation, and Osteogenic Differentiation of a Mouse Mesenchymal Stem Cell Line (BMC9) Seeded on Novel Melt-Based Chitosan/Polyester 3D Porous Scaffolds

“…It is in this context that natural-based polymers have been put forward in the last few years. Within this group, the polysaccharides, like starch, [20][21][22] and chitosan, [23][24][25][26][27][28][29] have been highlighted as the most promising, as they may act as analogs of polysaccharides present in vivo and adopt their roles. 27 An example of such affinity is the structural similarity observed between chitosan and glycosaminoglycans.…”

“…27 An example of such affinity is the structural similarity observed between chitosan and glycosaminoglycans. 28 Several reports about chitosan, [23][24][25][26][27][28][29] the alkaline deacetylated product of chitin, have shown that this polymer might have a range of interesting properties, from biodegradability to biocompatibility, considered to be suitable for bone tissue engineering scaffolding. Nevertheless, chitosan still presents a challenge when compared to other materials, that is, the inability of being processed by means other than by solventbased technology, which frequently leads to the development of scaffolds with poor mechanical properties and insufficient control of its morphology.…”