Towards Complex Tissues Replication: Multilayer Scaffold Integrating Biomimetic Nanohydroxyapatite/Chitosan Composites

Bioengineering (Basel). 2024 May 9;11(5):471. doi: 10.3390/bioengineering11050471.

Abstract

This study explores an approach to design and prepare a multilayer scaffold mimicking interstratified natural tissue. This multilayer construct, composed of chitosan matrices with graded nanohydroxyapatite concentrations, was achieved through an in situ biomineralization process applied to individual layers. Three distinct precursor concentrations were considered, resulting in 10, 20, and 30 wt% nanohydroxyapatite content in each layer. The resulting chitosan/nanohydroxyapatite (Cs/n-HAp) scaffolds, created via freeze-drying, exhibited nanohydroxyapatite nucleation, homogeneous distribution, improved mechanical properties, and good cytocompatibility. The cytocompatibility analysis revealed that the Cs/n-HAp layers presented cell proliferation similar to the control in pure Cs for the samples with 10% n-HAp, indicating good cytocompatibility at this concentration, while no induction of apoptotic death pathways was demonstrated up to a 20 wt% n-Hap concentration. Successful multilayer assembly of Cs and Cs/n-HAp layers highlighted that the proposed approach represents a promising strategy for mimicking multifaceted tissues, such as osteochondral ones.

Keywords: biomineralization; chitosan; hydroxyapatite; multilayered scaffolds.

Grants and funding

This work was partially supported by the Italian Ministry of Research (MUR) under complementary actions to the NRRP “FIT4MedRob” (Grant PNC0000007, CUP B53C22006960001) and “D34 Health” (contract number, CUP B53C22006100001), as well as from the “Tecnopolo per la medicina di precisione” (TecnoMed Puglia)—Regione Puglia DGR n.2117 del 21/11/2018 (CUP: B84I18000540002) and the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 953121 (FLAMIN-GO).