Polycaprolactone strengthening keratin/bioactive glass composite scaffolds with double cross-linking networks for potential application in bone repair

Abstract

In this study, we aimed at constructing polycaprolactone (PCL) reinforced keratin/bioactive glass composite scaffolds with a double cross-linking network structure for potential bone repair application. Thus, the PCL-keratin-BG composite scaffold was prepared by using keratin extracted from wool as main organic component and bioactive glass (BG) as main inorganic component, through both cross-linking systems, such as the thiol-ene click reaction between abundant sulfhydryl groups of keratin and the unsaturated double bond of 3-methacryloxy propyltrimethoxy silane (MPTS), and the amino-epoxy reaction between amino groups of keratin and the epoxy group in (3-glycidoxymethyl) methyldiethoxysilane (GPTMS) molecule, along with introduction of PCL as a reinforcing agent. The success of the thiol-ene reaction was verified by the FTIR and 1H-NMR analyses. And the structure of keratin-BG and PCL-keratin-BG composite scaffolds were studied and compared by the FTIR and XRD characterization, which indicated the successful preparation of the PCL-keratin-BG composite scaffold. In addition, the SEM observation, and contact angle and water absorption rate measurements demonstrated that the PCL-keratin-BG composite scaffold has interconnected porous structure, appropriate pore size and good hydrophilicity, which is helpful to cell adhesion, differentiation and proliferation. Importantly, compression experiments showed that, when compared with the keratin-BG composite scaffold, the PCL-keratin-BG composite scaffold increased greatly from 0.91 ± 0.06 MPa and 7.25 ± 1.7 MPa to 1.58 ± 0.21 MPa and 14.14 ± 1.95 MPa, respectively, which suggesting the strong reinforcement of polycaprolactone. In addition, the biomineralization experiment and MTT assay indicated that the PCL-keratin-BG scaffold has good mineralization ability and no-cytotoxicity, which can promote cell adhesion, proliferation and growth. Therefore, the results suggested that the PCL-keratin-BG composite scaffold has the potential as a candidate for application in bone regeneration field. Graphical Abstract

Effect of Keratin Waste on Poly(ε-Caprolactone) Films: Structural Characterization, Thermal Properties, and Keratinocytes Viability and Proliferation Studies

“…As reported in Figure 8, HaCaTs cultured on both PCL films and those enriched with different weight percentages of KE (10%, 15%, 25%, and 30%) were viable during the culture period (5 days). In particular, HaCaTs cultured on pure PCL films did not show any significant differences with regard to the control, without film, on day 1, while significant differences were observed in cell proliferation rates on days 3 and 5 [28]. The HaCaTs cultured on PCL films enriched with different weight percentages of KE showed significant differences with regard to the control, without film, on days 1, 3, and 5.…”

“…The combination of mammalian keratin with PCL has been already reported in the literature as useful for biomedical applications including tissue engineering [20,21], vascular engineering [22][23][24], vascular graft [25], wound healing [26], skin regeneration [27], and bone repair [28]. However, while the use of mammalian keratin with polymers has been largely reported in the literature [29], the combination of chicken keratin with polymeric materials has been studied to a lesser extent.…”

Periodontal bone regeneration with a degradable thermoplastic HA/PLCL bone graft

“…Incorporating bioceramics into appropriate biodegradable matrices is an efficient method to enhance the mechanical characteristics and biodegradability. [14][15][16][17][18] Lactide-caprolactone copolymer (PLCL) is an optimum choice for degradable matrices due to its ameliorated thermal and mechanical properties, tunable biodegradability, and bioactivity. [19][20][21][22][23] Ural et al loaded HA in a PLCL to produce a novel composite, which initiated new bone formation in rats and showed no adverse effects.…”

Mussel-inspired polydopamine decorated silane modified-electroconductive gelatin-PEDOT:PSS scaffolds for bone regeneration

“…GPTMS is suitable for chemical cross-linking because it contains amine-friendly coupling agents and hydrolysable functional groups. 18 A water-resistant bond is formed between the oxirane rings of GPTMS and the amino groups of gelatins, thereby cross-linking the structure and forming an organic–inorganic interface. 19 The presence of these bonds creates a nanoscale interaction between the organic and inorganic networks that enhances the in vivo stability of scaffolds.…”