Novel osteogenic growth peptide C-terminal pentapeptide grafted poly(d,l-lactic acid) improves the proliferation and differentiation of osteoblasts: The potential bone regenerative biomaterial

[Electrospun PLGA scaffold loaded with osteogenic growth peptide accelerates cranial bone repair in rats]

OBJECTIVE

To study the feasibility of electrospun poly(D, L-lactide-co-glycolide) (PLGA) scaffold loaded with osteogenic growth peptide (OGP) for bone tissue engineering.

METHODS

PLGA scaffolds were prepared by electrospinning PLGA solution without OGP(control group)or with 0.1%, 0.2%and 0.4%OGP(0.1%OGP@PLGA, 0.2%OGP@PLGA, and 0.4%OGP@PLGA scaffolds, respectively).The microstructure of the scaffolds was observed by scanning electron microscopy(SEM).The scaffolds were soaked in PBS to confirm the release pattern of OGP.The biocompatibility of the scaffolds was evaluated using CCK-8 assay and live/dead staining after a 7-day coculture with rat bone marrow-derived mesenchymal stem cells(BMSCs).ALP assay and ARS staining were used to evaluate osteoinduction capacity of the scaffolds co-cultured with rat BMSCs for 14 days.In a male SD rat model of skull defect(5 mm in diameter), bone defect repair was evaluated 8 weeks after implantation of the scaffolds using Micro-CT, HE and Masson staining.

RESULTS

The electrospun scaffolds had a fibrous structure similar to extracellular matrix(ECM)and were capable of sustained release of OGP for at least one month.Co-culture with 0.2%OGP@PLGA and 0.4%OGP@PLGA scaffolds, as compared with pure PLGA scaffold, significantly promoted the growth of rat BMSCs ((P < 0.01).The cells co-cultured with 0.4%OGP@PLGA scaffold showed the highest ALP activity and the greatest number of calcium nodules, indicating its strong osteoinduction ability (P < 0.01).Micro-CT and HE and Masson staining results showed that 0.4%OGP@PLGA scaffold had significantly better ability for promoting bone repair than the other two OGP-loaded scaffolds(P < 0.01).

CONCLUSION

The electrospun PLGA scaffold loaded with OGP effectively mimics the structure of ECM and has a good biocompatibility and osteoinduction ability, suggesting its potential as a new bone tissue engineering scaffold for bone defect repair.

A novel bio-inspired conductive, biocompatible, and adhesive terpolymer based on polyaniline, polydopamine, and polylactide as scaffolding biomaterial for tissue engineering application

A novel electrically conductive nanofibrous scaffold based on polyaniline-co-(polydopamine-grafted-poly(d,l-lactide)) [PANI-co-(PDA-g-PLA)] was fabricated using electrospinning technique and its physicochemical as well as biological characteristics toward bone tissue engineering (TE) were investigated extensively. In detail, PANI-co-PDA was synthesized via a one-step chemical oxidization approach. Then, d,l-lactaide monomer was grafted onto PDA segment using a ring opening polymerization (ROP) to afford PANI-co-(PDA-g-PLA) terpolymer. The successful synthesis of PANI-co-(PDA-g-PLA) terpolymer was confirmed using FTIR spectroscopy as well as TGA analysis. Finally, a solution of the synthesized terpolymer was electrospun to fabricate a conductive nanofibrous scaffold. Some physicochemical features such as mechanical, conductivity, electroactivity, hydrophobicity, and morphology as well as biological characteristics including biocompatibility, biodegradability, as well as enhancing the cells adhesion and proliferation were investigated. According to the above-mentioned experimental results, the fabricated electrospun nanofibers can be considered as a potential scaffold for TE application, mainly due to its proper physicochemical and biological properties.