Preparation of simvastatin loaded nanoparticles by microfluidic and embedding it on the Chitosan-Gelatin- Clinoptilolite-Hydroxyapatite scaffold and its evaluation in bone tissue regeneration

Abstract

Treating bone defects with tissue engineering is a promising approach. Recently, simvastatin has been considered as a factor in bone cell growth. However, the investigations on its effective loading and delivering is minor. Main aim: The aim of this study was formation of nanoparticles through self-assembly of block copolymers using microfluidic. We proposed that PLLA-PEG-PLLA nanoparticles may be used to maximum SIM loading and release rate prolonged. Therefore, we synthesized a biodegradable PLLA-PEG-PLLA nanoparticle by using microfluidic system. Moreover, this nanoparticle embedded on the CG-nHA scaffold, and the effects of PLLA-PEG-PLLA-SIM was studied on the differentiation of human dental pulp stem cells (h-DPSCs) to osteogenic. Procedure: Firstly, the scaffold of chitosan-gelatin-nanohydroxy apatite was fabricated. Bioceramic clinoptilolite added to chitosan-gelatin-nanohydroxyapatite scaffold. Microfluidic chip design, PLLA-PEG-PLLA carrier synthesis and simvastatin loading into the carrier were performed using microfluidic chip. H-DPSCs were seeded to the scaffold and the differentiation of dental pulp cells to bone was assessed by alizarin red, alkalin phosphate, and molecular RT-PCR methods. Results: By adding bioceramic clinoptilolite to chitosan-gelatin-nanohydroxyapatite scaffold, its physicochemical properties for use in bone tissue engineering were improved. This nanoparticle showed low polydispersity and release rate, high drug loading and encapsulating, and specified size. By examining the bone genes RUNX2, OC and BMP2, the differentiation of dental pulp cells into bone was determined. Conclusion: We synthesized a biodegradable PLLA-PEG-PLLA nanoparticle by using microfluidic system and loaded-SIM in it. This nanoparticle showed that rapid and adjustable microfluidic mixing provides nanoparticles with lower polydispersity, higher drug encapsulating, and specified size. Moreover, the result RT-PCR showed that scaffolds treated with PLLA-PEG-PLLA nanoparticles were more differentiated to osteogenic than CS-G/nHA-CLN scaffolds treated with PLLA-PEG nanoparticles on day 21 after culture.