Development of a double-layer electrospun patch as a potential prenatal treatment for myelomeningocele.

Myelomeningocele (MMC) is a congenital defect of the spine characterised by meningeal and spinal cord protrusion through the open vertebral arches. This defect causes progressive prenatal damage of the spinal cord, leading to lifelong handicap. Although mid-trimester surgical repair may reduce part of the handicap, an earlier and less invasive approach would further improve the prognosis, possibly minimising maternal and foetal risks. Several studies have proposed an alternative approach to surgical repair by covering the defect with a patch and protecting the exposed neural tissue. Our study aims to elaborate on a waterproof and biodegradable bioactive patch for MMC prenatal foetal repair. We developed a double-layer patch that can provide a waterproof coverage for the spinal cord, with a bioactive side, conducive to cell proliferation, and an antiadhesive side to avoid its attachment to the medulla.

Characterization of plasmatic proteins adsorption on poly(styrene sodium sulfonate) functionalized silicone surfaces.

Proteins adsorption occurs spontaneously on biomaterial upon insertion within the body. The resulting protein layer influences biomaterial biocompatibility through enhanced bio-integration or, on the contrary, adverse reactions. Furthermore, upon adsorption, proteins can undergo modifications of their structure and, ultimately, their physicochemical properties and activity. Hence, the understanding of protein adsorption on implanted materials appears essential, as exemplified by silicone breast prostheses that might lead to serious health issues. Surface modifications with a bioactive polymer, poly(styrene sodium sulfonate)-polyNaSS, on a hydrophobic silicone surface that composes breast implants, have been successfully performed under UV irradiation by a radical surface polymerization. This strategy enhances cell biocompatibility and antibacterial features. Although detailed insights related to the mechanism are still scarce, polyNaSS is supposed to promote changes in the conformation and/or orientation of adsorbed plasma proteins, reducing the odd for a biofilm to form. The present work addresses more in-depth structural investigations of the adsorbed state of two plasma proteins: Bovine Serum Albumin (BSA), as a model protein, and fibronectin (FN), for its role in cell adhesion. Using Atomic force microscopy (AFM), we report that polyNaSS showed no significant impact on the BSA structure conversely to the FN one. However, imaging findings with AFM clearly outlined a change in the structural organization of FN, going from a nano fibrillar assembly with an average length of 130 nm to a globular one when the surface was grafted. Thus, it is highlighted that polyNaSS interacts specifically with FN. In addition, cell spreading assay of L929 fibroblasts on FN-coated surfaces with optical microscopy indicated no significant impact of the change in FN structure upon fibroblasts adhesion, which displayed active elongated shapes. The present features are crucial for understanding the cell adhesion mechanism induced by surface modification.

Review of titanium surface modification techniques and coatings for antibacterial applications.

Implanted biomaterials play a key role in the current success of orthopedic and dental procedures. Pure titanium and its alloys are the most commonly used materials for permanent implants in contact with bone. However, implant-related infections remain among the leading reasons for failure. The most critical pathogenic event in the development of infection on biomaterials is biofilm formation, which starts immediately after bacterial adhesion. In the last decade, numerous studies reported the ability of titanium surface modifications and coatings to minimize bacterial adhesion, inhibit biofilm formation and provide effective bacterial killing to protect implanted biomaterials. In the present review, the different strategies to prevent infection onto titanium surfaces are reported: surface modification and coatings by antibiotics, antimicrobial peptides, inorganic antibacterial metal elements and antibacterial polymers. STATEMENT OF SIGNIFICANCE: Implanted biomaterials play a key role in the current success of orthopedic and dental procedures. Pure titanium and its alloys are the most commonly used materials for permanent implants in contact with bone. Microbial infection is one of the main causes of implant failure. Currently, the global infection risk is 2-5% in orthopedic surgery. Numerous solutions exist to render titanium surfaces antibacterial. The LBPS team is an expert on the functionalization of titanium surfaces by using bioactive polymers to improve the biologiocal response. In this review, the different strategies to prevent infection are reported onto titanium and titanium alloy surfaces such as surface modification by antibiotics, antimicrobial peptides, inorganic antibacterial metal elements and antibacterial polymers.

A green and bio-inspired process to afford durable anti-biofilm properties to stainless steel.

A bio-inspired durable anti-biofilm coating was developed for industrial stainless steel (SS) surfaces. Two polymers inspired from the adhesive and cross-linking properties of mussels were designed and assembled from aqueous solutions onto SS surfaces to afford durable coatings. Trypsin, a commercially available broad spectrum serine protease, was grafted as the final active layer of the coating. Its proteolytic activity after long immersion periods was demonstrated against several substrata, viz. a synthetic molecule, N-α-benzoyl-DL-arginine-p-nitroanilide hydrochloride (BAPNA), a protein, FTC-casein, and Gram-positive biofilm forming bacterium Staphylococcus epidermidis.