Molecular spectroscopy analysis of the substitution of bone tissue by HAp/PLLA composite biomaterial

Abstract

Due to its pronounced osteoinductive properties, calcium hydroxyapatite (HAp) has been widely used in medicine. Bioresorptive poly-L-lactide (PLLA) as a polymer biomaterial has been also used extensively in medicine for its non-toxicity and biocompatibility. To combine the advantages exhibited by each of these materials, a HAp/PLLA composite biomaterial has been synthesized and used for reconstruction and repair of bone defects. Hydroxyapatite/poly-L-lactide (HAp/PLLA) composite biomaterial with PLLA of 50,000 and 430,000 g/mole molecular weight was studiedin vivo. The biocomposite with PLLA of both molecular weights was implanted into mice, then removed from their organisms and analyzed by the Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and histopathologic analysis. Characteristic absorption bands, registered and defined by FT-IR spectroscopy, confirm the formation of new functional groups and compounds during the bone repair process using HAp/PLLA biocomposite with PLLA of 50,000 and 430,000 molecular weights. Analysis of the microstructures of the sample surfaces by scanning electron microscopy (SEM) before and after implantation revealed bioresorption of the PLLA polymer phase in the system with PLLA of lower molecular weight and generation of collagen fibers at the sites of implanted bioresorptive PLLA. As the studied synthetic materials behave as the natural bone, i.e., they are phagocytosed and resorpable, they can be considered as biocompatible.

Multifunctional hydroxyapatite and poly(d,l-lactide-co-glycolide) nanoparticles for the local delivery of cholecalciferol

“…The FT-IR spectrum of HAp is defined by a doublet with maxima at 1035 and 1092 cm −1 and by a triplet with most pronounced maxima at 561 and 603 cm −1 , all of which are due to vibrations of the phosphate group. The bands with maxima at 632 and 3567 cm −1 are caused by the vibrations of the hydroxyl group in the crystal lattice of HAp [30]. Cholecalciferol is typified by the CH 3 asymmetric stretching mode and the CH 2 symmetric stretching mode at 2943 and 2875 cm −1 , respectively [31,32], the two bands that are observable in our spectrum of the vitamin too.…”

Chirality‐Induced Bionic Scaffolds in Bone Defects Repair—A Review

“…[70] What is more, the synergistic effect of HA and collagen can make hMSCs quickly differentiate into osteoblasts, showing excellent osteoinduction properties. [71] In addition to electrospinning, there are other special methods and processes used to produce HA/PLLA, such as electrodeposition, [72] in situ precipitation, [73,74] emulsion method, [75] drop-condensation, [76] and special processes based on surface etching, [77] bionic coating, [59] and hot pressing. [78,79] The HA/PLLA composite bionic scaffold prepared by methods mentioned above have to face two problems.…”

“…Meanwhile, ADSCs are abundant, easily accessible, and the disease incidence of them are low. In addition, Kim et al [59] successfully prepared modulated HA/PLLA without reducing mechanical properties. The technique of converting Mg to HA imbedded HA into PLLA substrates, which improved biological activity of this scaffolds and effectively avoided the risk of coating stratification.…”

“…bone defects. [59] Spectral analysis of their structure demonstrated the formation of new compounds and functional groups after implantation. Obvious production of collagen fiber was observed around the implant and there was no significant inflammatory response.…”

“…The composite bionic scaffolds constructed by the most widely used bioceramic nHA and α ‐hydroxy carboxylic acid PLLA were used as bone tissue substitutes for the first time in mice with bone defects. [ 59 ] Spectral analysis of their structure demonstrated the formation of new compounds and functional groups after implantation. Obvious production of collagen fiber was observed around the implant and there was no significant inflammatory response.…”