Polyglobalide-Based Porous Networks Containing Poly(ethylene glycol) Structures Prepared by Photoinitiated Thiol–Ene Coupling

Cellulosic Textiles-An Appealing Trend for Different Pharmaceutical Applications

Cellulose, the most abundant biopolymer in nature, is derived from various sources. The production of pharmaceutical textiles based on cellulose represents a growing sector. In medicated textiles, textile and pharmaceutical sciences are integrated to develop new healthcare approaches aiming to improve patient compliance. Through the possibility of cellulose functionalization, pharmaceutical textiles can broaden the applications of cellulose in the biomedical field. This narrative review aims to illustrate both the methods of extraction and preparation of cellulose fibers, with a particular focus on nanocellulose, and diverse pharmaceutical applications like tissue restoration and antimicrobial, antiviral, and wound healing applications. Additionally, the merging between fabricated cellulosic textiles with drugs, metal nanoparticles, and plant-derived and synthetic materials are also illustrated. Moreover, new emerging technologies and the use of smart medicated textiles (3D and 4D cellulosic textiles) are not far from those within the review scope. In each section, the review outlines some of the limitations in the use of cellulose textiles, indicating scientific research that provides significant contributions to overcome them. This review also points out the faced challenges and possible solutions in a trial to present an overview on all issues related to the use of cellulose for the production of pharmaceutical textiles.

Synthesis of Functionalized Triblock Copolyesters Derived from Lactic Acid and Macrolactones for Bone Tissue Regeneration

Synthetic and functional grafts are a great alternative to conventional grafts. They can provide a physical support and the precise signaling for cells to heal damaged tissues. In this study, a novel RGD peptide end-functionalized poly(ethylene glycol)-b-poly(lactic acid)-b-poly(globalide)-b-poly(lactic acid)-b-poly(ethylene glycol) (RGD-PEG-PLA-PGl-PLA-PEG-RGD) is synthetized and used to prepare functional scaffolds. The PGl inner block is obtained by enzymatic ring-opening polymerization of globalide. The outer PLA blocks are obtained by ring-opening polymerization of both, l-lactide or a racemic mixture, initiated by the α-ω-telechelic polymacrolactone. The presence of PGl inner block enhances the toughness of PLA-based scaffolds, with an increase of the elongation at break up to 300% when the longer block of PGl is used. PLA-PGl-PLA copolymer is coupled with α-ω-telechelic PEG diacids by esterification reaction. PEGylation provides hydrophilic scaffolds as the contact angle is reduced from 114° to 74.8°. That difference improves the contact between the scaffolds and the culture media. Moreover, the scaffolds are functionalized with RGD peptides at the surface significantly enhancing the adhesion and proliferation of bone marrow-derived primary mesenchymal stem cells and MC3T3-E1 cell lines in vitro. These results place this multifunctional polymer as a great candidate for the preparation of temporary grafts.

Foldable Bulk Anti-adhesive Polyacrylic Intraocular Lens Material Design and Fabrication for Posterior Capsule Opacification Prevention

Posterior capsular opacification (PCO) is a primary complication after phacoemulsification combined with intraocular lens (IOL) implantation, which is attributed to adhesion, proliferation, and migration of residual lens epithelial cells on IOL. Although surface hydrophilic coating is considered to be a powerful way to inhibit PCO incidence after surgery, it requires complex post-production processes, thus limiting their applicability. In comparison, bulk modification is a stable, effective, and facile IOL synthesis method for PCO prevention. Herein, a new anti-adhesive IOL material was designed and successfully synthesized by radical copolymerization of ethylene glycol phenyl ether methacrylate (EGPEMA) and 2-(2-ethoxyethoxy) ethyl acrylate (EA). The physicochemical properties of P(EGPEMA-co-EA) copolymer materials, including chemical structure, mechanical, thermal, surface, and optical properties, were analyzed by using ¹H NMR spectroscopy, FT-IR spectroscopy, tensile test, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), water contact angle measurement, and UV-vis spectroscopy. The elongation at break and the modulus of elasticity of the copolymer were tunable through the change of the composition of monomers. Compared to other components, the tensile results showed that P(EGPEMA-co-EA) materials (70% EGPEMA in mass ratio, F7) are suitable for the preparation of foldable intraocular lens with lower elastic modulus and higher elongation at break. TGA and DSC showed that the material has high thermal stability, and the glass transition temperature of F7 material is 16.1 °C. The water contact angle measurement results showed that the introduction of EA improved the hydrophilicity of the material. The percentage of transmittance of all copolymers at 400-800 nm is above 85%. Then, the biocompatibility of the materials was evaluated by in vitro assay and subcutaneous implantation. Both in vitro results and subcutaneous implantation experiments showed that the designed IOL materials exhibited a good anti-adhesion effect and no cytotoxicity. Finally, phacoemulsification and IOL intraocular implantation were performed, and the in vivo results confirmed the good PCO prevention ability as well as the biocompatibility of the new IOL materials.

Enzymatic recycling of polymacrolactones

The use of renewable monomers to make new polyesters which could replace the ones obtained from petrochemical resources employing green processes is a big concern in these days. With this...

Versatility of unsaturated polyesters from electrospun macrolactones: RGD immobilization to increase cell attachment

Poly(globalide) (PGl), an aliphatic polyester derived from unsaturated macrocylic lactone, can be cross-linked during electrospinning and drug-loaded for regenerative medicine applications. However, it lacks intrinsic recognition sites for cell adhesion and proliferation. In order to improve their cell adhesiveness, and therefore their therapeutic potential, we aimed to functionalize electrospun PGl fibers with RGD sequence generating a biomimetic scaffold. First, an amine compound was attached to the surface double bonds of the PGl fibers. Subsequently, the amino groups were coupled with RGD sequences. X-ray photoelectron spectroscopy (XPS) analysis confirmed the functionalization. The obtained fibers were more hydrophilic, as observed by contact angle analysis, and presented smaller Young's modulus, although similar tensile strength compared with non-functionalized cross-linked fibers. In addition, the functionalization process did not significantly alter fibers morphology, as observed by scanning electron microscopy (SEM). Finally, in vitro analysis evidenced the increase in human mesenchymal stromal cells (hMSC) adhesion (9.88 times higher DNA content after 1 day of culture) and proliferation (3.57 times higher DNA content after 8 days of culture) compared with non-functionalized non-cross-linked fibers. This is the first report demonstrating the functionalization of PGl fibers with RGD sequence, improving PGl therapeutic potential and further corroborating the use of this highly versatile material toward regenerative medicine applications.

Polyesters with main and side chain phosphoesters as structural motives for biocompatible electrospun fibres

The functionalisation of polymacrolactones with phosphoesters was achieved by thiol–ene coupling resulting in copolymers with modulated properties.

Crosslinking of Electrospun Fibres from Unsaturated Polyesters by Bis-Triazolinediones (TAD)

Crosslinking of an unsaturated aliphatic polyester poly(globalide) (PGl) by bistriazolinediones (bisTADs) is reported. First, a monofunctional model compound, phenyl-TAD (PTAD), was tested for PGl functionalisation. 1H-NMR showed that PTAD-ene reaction was highly efficient with conversions up to 97%. Subsequently, hexamethylene bisTAD (HM-bisTAD) and methylene diphenyl bisTAD (MDP-bisTAD) were used to crosslink electrospun PGl fibres via one- and two-step approaches. In the one-step approach, PGl fibres were collected in a bisTAD solution for in situ crosslinking, which resulted in incomplete crosslinking. In the two-step approach, a light crosslinking of fibres was first achieved in a PGl non-solvent. Subsequent incubation in a fibre swelling bisTAD solution resulted in fully amorphous crosslinked fibres. SEM analysis revealed that the fibres' morphology was uncompromised by the crosslinking. A significant increase of tensile strength from 0.3 ± 0.08 MPa to 2.7 ± 0.8 MPa and 3.9 ± 0.5 MPa was observed when PGI fibres were crosslinked by HM-bisTAD and MDP-bisTAD, respectively. The reported methodology allows the design of electrospun fibres from biocompatible polyesters and the modulation of their mechanical and thermal properties. It also opens future opportunities for drug delivery applications by selected drug loading.