The grafting of a thin layer of poly(sodium styrene sulfonate) onto poly(ε-caprolactone) surface can enhance fibroblast behavior

Abstract

Poly(sodium styrene sulfonate) (pNaSS) was grafted onto poly(ε-caprolatone) (PCL) surfaces via ozonation and graft polymerization. The effect of ozonation and polymerization time, as well as the Mohr’s salt concentration in the grafting solution, on the degree of grafting was investigated. The degree of grafting was determined through toluidine blue staining. The surface chemical change was characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The result demonstrated that the grafting did not induce any degradation of PCL, and that pNaSS was grafted onto PCL as a thin and covalently stable layer. Furthermore, the modified PCL surface reveals a significant increase in the metabolic activity of fibroblastic cells, as well as a better cell spreading with higher adhesion strength. Consequently, bioactivity of PCL is greatly enhanced by immobilizing a thin layer of pNaSS onto its surface. The grafting of pNaSS is a promising approach to increase the bioactivity of PCL-based materials used in tissue engineering applications, such as ligament reconstruction.

Biomaterial-Guided Recombinant Adeno-associated Virus Delivery from Poly(Sodium Styrene Sulfonate)-Grafted Poly(ɛ-Caprolactone) Films to Target Human Bone Marrow Aspirates

“…The poly(-caprolactone) (PCL) films were prepared by spin-coating method. 51 A PCL solution in dichloromethane (60% (w/v)) was dropped on a glass slide and spun for 30 sec at 1,500 rpm using a SPIN150-v3 SPS. The films were air-dried for 2 h, vacuum-dried for 24 h, and cut into 4-mm disks.…”

“…Among the large variety of solid scaffolds available in cartilage research, 47 those based on the biocompatible, FDA-approved aliphatic polyester poly(caprolactone) (PCL) 48,49 present significant advantages as this low immunogenic, biodegradable compound can mimic the anisotropic and viscoelastic biomechanical features of the articular cartilage. 50 In the present study, we manipulated PCL films to further graft their surface with poly(sodium styrene sulfonate) (pNaSS), a bioactive polymer that facilitates protein adsorption and stimulates reparative cellular responses (adhesion, proliferation), 51 as potential materials to genetically modify clinical marrow samples via controlled delivery of recombinant AAV (rAAV) vectors over time. Our data demonstrate that pNaSS-grafted PCL films provide functional systems capable of supporting the effective, durable, and not cytotoxic transfer of reporter rAAV vectors in human bone marrow aspirates relative to control (vectorfree) conditions, reaching levels similar to or higher than those noted using ungrafted films or upon free vector treatment.…”

Enhanced Chondrogenic Differentiation Activities in Human Bone Marrow Aspirates via sox9 Overexpression Mediated by pNaSS-Grafted PCL Film-Guided rAAV Gene Transfer

“…The poly(ε-caprolactone) (PCL) films were prepared by spin-coating as previously described [38]. Briefly, a PCL solution (60% (w/v) in dichloromethane) was dropped on a glass slide for spinning (30 sec, 1,500 rpm) with a SPIN150-v3 SPS and the films were air-dried for 2 h and next vacuum-dried for 24 h. The films were then cut in 4-mm disks and some films were grafted with pNaSS (1.3 × 10 −5 mol/g) via ozonation (10 min, 30 • C).…”

“…As a matter of fact, a number of studies reported the potential of applying rAAV for experimental cartilage research via hydrogel systems (alginate, fibrin, poloxamers/poloxamines, self-assembling peptides, polypseudorotaxanes) [25][26][27][28][29][30][31][32][33] while there is still little information on the potential benefits of solid, mechanically more stable biomaterials that may provide scaffolding and stability to the target cells [34] for rAAV-mediated gene transfer. In this regard, we recently provided evidence that biocompatible solid polyester poly(ε-caprolactone) (PCL) [35], an aliphatic polyester approved by the FDA [36,37], further grafted with poly(sodium styrene sulfonate) (pNaSS) to activate reparative cellular responses [38] is capable of supporting the delivery of reporter rAAV gene vectors to effectively modify human bone marrow aspirates [39]. The goal of the present study was therefore to further test the ability of pNaSS-grafted PCL films to directly deliver a therapeutic rAAV vector coding for the cartilage-specific sex-determining region Y-type high mobility group box 9 (SOX9) transcription factor [40] in marrow aspirates as a means to trigger the chondroreparative activities in these samples in light of our earlier work showing that rAAV SOX9 can restore the extracellular matrix in human osteoarthritic cartilage [41].…”

Analysis of early cellular responses of anterior cruciate ligament fibroblasts seeded on different molecular weight polycaprolactone films functionalized by a bioactive poly(sodium styrene sulfonate) polymer

“…This observation confirmed the mechanism of grafting presented by Ciobanu et al [29] and Rohman and al. [33] which started with an oxidation of the surface to generate peroxide and hydro-peroxide functions followed by radical polymerization of NaSS. Table 3.…”