Biosoluble ceramic fiber reinforced poly(L-lactic acid) bone scaffold: degradation and bioactivity

Abstract

Poly (l-lactic acid) (PLLA) exhibits great potential as a kind of scaffold material for bone defect repair because of its good biocompatibility and processability, while the too slow degradation rate hinders its further application. In this study, the biosoluble ceramic fiber (BCF) was introduced into PLLA matrix, and the PLLA/BCF composite scaffold was manufactured by selective laser sintering (SLS). It was observed that water contact angle of the composite scaffold decreased from 87.4° to 61.1° with the increasing content of BCF, while the pH value raised from 6.6 to 7.8, and the molecular weight of PLLA decreased after immersion for 4 weeks. The mechanism of degradation acceleration was that the dissolution of BCF not only released OH− into solution environment and produced alkaline microenvironment, but also formed capillary channels on the interface between BCF and PLLA matrix, beneficial for the infiltration of water into the hydrophobic PLLA matrix, which contributed to the degradation both on the surface and in the interior of the matrix. Besides, the dissolution of BCF released Ca2+, Si2+ and Mg2+ simultaneously and absorbed PO43− from the environment, contributing to the formation of bone bonding between the scaffold and host bone. In addition, the introduced BCF improved the mechanical capacities of the scaffold via fiber breakage, fiber debond and fiber separation, and so on.

Structural and Functional Adaptive Artificial Bone: Materials, Fabrications, and Properties

“…In addition, BCF contains a large number of Ca elements, which can combine with PO 4 3− to form calcium and phosphorus layer in the body fluid environment and enhance the binding with natural bone. [ 224 ]…”

“…A) Water climbed along the surface of BCF, B) Water contact angles of PLLA scaffold with different BCF content, C) Weight loss of PLLA scaffold with different BCF content after immersion in Phosphate buffer saline (PBS) for 4 weeks. D) pH variation of the solution after scaffold immersion, E) The schematic of BCF accelerating PLLA bone scaffold degradation and mineralization.Reproduced with permission [224]. Copyright 2022, Springer Nature.…”

Preparation of nanofibrous poly (L-lactic acid) scaffolds using the thermally induced phase separation technique in dioxane/polyethylene glycol solution

“…Specifically, PLLA has been widely used for bone, blood vessel, and cardiac tissue replacement [ 19–23 ]. However, PLLA has some disadvantages, such as the hydrophobicity of the material surface, the acidic nature of the degradation product, and the fact that the rate of degradation is not similar to the rate of bone regeneration [ 24 ]. Hydroxyapatite (HA) is an inorganic, weakly alkaline mineral that is an important part of the bone and teeth, and accounts for about 65% of the total weight in bone quality.…”