Injectable Chitosan-Based Hydrogels for Trans-Cinnamaldehyde Delivery in the Treatment of Diabetic Foot Ulcer Infections.

Diabetic foot ulcers (DFU) are among the most common complications in diabetic patients and affect 6.8% of people worldwide. Challenges in the management of this disease are decreased blood diffusion, sclerotic tissues, infection, and antibiotic resistance.

Evaluation of a Medical Grade Thermoplastic Polyurethane for the Manufacture of an Implantable Medical Device: The Impact of FDM 3D-Printing and Gamma Sterilization.

Three-dimensional printing (3DP) of thermoplastic polyurethane (TPU) is gaining interest in the medical industry thanks to the combination of tunable properties that TPU exhibits and the possibilities that 3DP processes offer concerning precision, time, and cost of fabrication. We investigated the implementation of a medical grade TPU by fused deposition modelling (FDM) for the manufacturing of an implantable medical device from the raw pellets to the gamma (γ) sterilized 3DP constructs. To the authors' knowledge, there is no such guide/study implicating TPU, FDM 3D-printing and gamma sterilization.

Milling-Assisted Loading of Drugs into Mesoporous Silica Carriers: A Green and Simple Method for Obtaining Tunable Customized Drug Delivery.

Mesoporous silica (MPS) carriers are considered as a promising strategy to increase the solubility of poorly soluble drugs and to stabilize the amorphous drug delivery system. The development by the authors of a solvent-free method (milling-assisted loading, MAL) made it possible to manipulate the physical state of the drug within the pores. The present study focuses on the effects of the milling intensity and the pore architecture (chemical surface) on the physical state of the confined drug and its release profile.

Electrospun Filtering Membrane Designed as Component of Self-Decontaminating Protective Masks.

The 2019 coronavirus outbreak and worsening air pollution have triggered the search for manufacturing effective protective masks preventing both particulate matter and biohazard absorption through the respiratory tract. Therefore, the design of advanced filtering textiles combining efficient physical barrier properties with antimicrobial properties is more newsworthy than ever. The objective of this work was to produce a filtering electrospun membrane incorporating a biocidal agent that would offer both optimal filtration efficiency and fast deactivation of entrapped viruses and bacteria.

Polydopamine treatment of chitosan nanofibers for the conception of osteoinductive scaffolds for bone reconstruction.

We report the influence of treatment time of electrospun chitosan nanofibers (CHT NFs) in dopamine hydrochloride bath (2 mg.mL in 10 mM Tris buffer, pH 8.5) on the extent of the polydopamine (pDA) coating on NFs surface.

In Vitro Microbiological and Drug Release of Silver/Ibuprofen Loaded Wound Dressing Designed for the Treatment of Chronically Infected Painful Wounds.

This study consisted of developing a dressing loaded with silver (Ag) and ibuprofen (IBU) that provides a dual therapy, antibacterial and antalgic, intended for infected painful wounds. Therefore, non-woven polyethyleneterephtalate (PET) textiles nonwovens were pre-treated by cyclodextrin crosslinked with citric acid by a pad/dry/cure process. Then, textiles were impregnated in silver solution followed by a thermal treatment and were then coated by Layer-by-Layer (L--L) deposition of a polyelectrolyte multilayer (PEM) system consisting of anionic water-soluble poly(betacyclodextrin citrate) (PCD) and cationic chitosan.

Manipulating the physical states of confined ibuprofen in SBA-15 based drug delivery systems obtained by solid-state loading: Impact of the loading degree.

Using the Milling-Assisted Loading (MAL) solid-state method for loading a poorly water-soluble drug (ibuprofen, IBP) within the SBA-15 matrix has given the opportunity to manipulate the physical state of drugs for optimizing bioavailability. The MAL method makes it easy to control and analyze the influence of the degree of loading on the physical state of IBP inside the SBA-15 matrix with an average pore diameter of 9.4 nm.

Release-killing properties of a textile modified by a layer-by-layer coating based on two oppositely charged cyclodextrin polyelectrolytes.

Infections represent a major medical concern and have severe impact on the public health economy. Antimicrobial coatings represent one major solution and are the subject of many investigations in academic and industrial research. Polyelectrolyte multilayers (PEMs) consist in the step-by-step deposition of polyanions and polycations films on surfaces.

Synthesis of novel catalytic composite nanofibers containing ruthenium nanoparticles stabilized by a citric acid-β-cyclodextrin polymer.

The elaboration of catalytic composite nanofibers (NFs) by electrospinning through a one-pot strategy is described. First, aqueous colloidal suspensions of ruthenium nanoparticles (Ru NPs) formed by reduction of a Ru(iii) salt with NaBH and stabilized by poly(cyclodextrin citrate) (PCD) were prepared. Then, poly(vinyl alcohol) (PVA) of different molecular weights was dissolved in the colloidal suspensions that were electrospun.

Stent coating by electrospinning with chitosan/poly-cyclodextrin based nanofibers loaded with simvastatin for restenosis prevention.

The main cause of failure of angioplasty stenting is restenosis due to neointimal hyperplasia, a too high proliferation of smooth muscle cells (SMC). The local and sustained delivery of selective pleiotropic drugs to limit SMC proliferation seems to be the hopeful solution to minimize this post surgery complication. The aim of this study is to develop a stent covered by nanofibers (NFs) produced by electrospinning, loaded with simvastatin (SV), a drug commonly used for restenosis prevention.

Evaluation of antibacterial textile covered by layer-by-layer coating and loaded with chlorhexidine for wound dressing application.

The aim of this work is to design a wound dressing able to release chlorhexidine (CHX) as antiseptic agent, ensuring long-lasting antibacterial efficacy during the healing. The textile nonwoven (polyethylene terephthalate) (PET) of the dressing was first modified by chitosan (CHT) crosslinked with genipin (Gpn). Parameters such as the concentration of reagents (Gpn and CHT) but also the crosslinking time and the working temperature were optimized to reach the maximal positive charges surface density.

In vitro evaluation of drug release and antibacterial activity of a silver-loaded wound dressing coated with a multilayer system.

The goal of the study was to elaborate an antibacterial silver wound dressing covered by a protective coating that would prevent silver diffusion toward skin without losing its biocide properties. Therefore, non woven polyethyleneterephtalate (PET) textiles were pre-treated by two types of polysaccharides - chitosan and cyclodextrin - both crosslinked with citric acid by a pad/dry/cure process. Both types of resulting thermofixed textiles carrying the citrate crosslinks were then impregnated in silver solution followed by a thermal treatment and were finally coated by Layer-by-Layer (L-b-L) deposition of a polyelectrolyte multilayer (PEM) film consisting of anionic water-soluble poly-cyclodextrin and cationic chitosan.

A detailed analysis of the influence of β-cyclodextrin derivates on the thermal denaturation of lysozyme.

The influence of HPβCD on the thermal denaturation of lysozyme was analyzed mainly from microcalorimetry and Raman investigations carried out in the molecular fingerprint and the low-frequency regions. It was shown that Raman spectroscopy investigations performed on a wide spectral range give the opportunity to describe the influence of HPβCD on the mechanism of protein denaturation. Using DO as solvent allowed us to show that HPβCD mainly destabilizes the tertiary structure of lysozyme by enhancing the protein flexibility and thus inducing the destabilization of the secondary structure.

Sulfonated and sulfated chitosan derivatives for biomedical applications: A review.

From 20th century, chitosan, a natural polysaccharide, has received much attention for use in biomedical applications thanks to its remarkable properties, such as biodegradability, biocompatibility, hemostasis and antibacterial activity. Over the last decades, many researchers have attempted to generate new chitosan derivatives-based biomaterials though chemical modifications, especially through sulfonation or sulfation reactions in order to tailor the physicochemical and biochemical properties. Due to the presence of residual amino groups, the generated polyampholytic derivatives are characterized by convenient biological properties, such as antioxidation, antiviral activity, anticoagulation and bone regeneration, expanding their application scope.

Synthesis and characterization of polyampholytic aryl-sulfonated chitosans and their in vitro anticoagulant activity.

This work firstly aimed to synthesize mono- and di- sulfonic derivatives of chitosan by reductive amination reaction using respectively 2-formyl benzene sulfonic acid and 2,4 formyl benzene sulfonic acid sodium salts. The influence of the reactants molar ratio (R), aryl - substituted amino groups versus chitosan free amino groups, on the degree of substitution (DS) of both sulfonated chitosans was assessed by H NMR, elemental analysis, coupled conductometry-potentiometry analysis and UV spectrometry and FTIR. The influence of pH on sulfonated chitosans' properties in solution were investigated by solubility and zeta potential (ZP) studies, size exclusion chromatography equipped with MALLS detection (SEC-MALLS) and Taylor dispersion analysis (TDA).

Preparation and characterization of novel chitosan and β-cyclodextrin polymer sponges for wound dressing applications.

Chitosan (CS) presents antibacterial, mucoadhesive and hemostatic properties and is an ideal candidate for wound dressing applications. This work reports the development of sponge-like materials obtained from physical hydrogels after the interaction between CS and a β-cyclodextrin polymer (PCD) in acidic conditions to provoke immediate gelation. Characterization consisted of zeta potential (ZP) measurements, rheology analysis, Fourier transform infrared (FTIR), Raman spectroscopy, wide angle X-ray scattering (WAXS) and scanning electron microscopy (SEM).

Triclosan loaded electrospun nanofibers based on a cyclodextrin polymer and chitosan polyelectrolyte complex.

This work focuses on the relevance of antibacterial nanofibers based on a polyelectrolyte complex formed between positively charged chitosan (CHT) and an anionic hydroxypropyl betacyclodextrin (CD)-citric acid polymer (PCD) complexing triclosan (TCL). The study of PCD/TCL inclusion complex and its release in dynamic conditions, a cytocompatibility study, and finally the antibacterial activity assessment were studied. The fibers were obtained by electrospinning a solution containing chitosan mixed with PCD/TCL inclusion complex.

Effect of different carboxylic acids in cyclodextrin functionalization of cellulose nanocrystals for prolonged release of carvacrol.

Current investigations deal with new surface functionalization strategy of nanocrystalline cellulose-based substrates to impart active molecule release properties. In this study, cellulose nanocrystals (CNC) were surface-functionalized with β-cyclodextrin (β-CD) using succinic acid (SA) and fumaric acid (FA) as bridging agents. The main objective of this surface modification performed only in aqueous media was to obtain new active materials able to release antibacterial molecules over a prolonged period of time.

New multifunctional pharmaceutical excipient in tablet formulation based on citric acid-cyclodextrin polymer.

A β-cyclodextrin (β-CD) polymer obtained by crosslinking β-CD with citric acid in its water-insoluble (PCD-I) and soluble (PCD-S) forms was used as a multifunctional direct compression excipient for tablet designing. PCD-I powder was obtained after grinding the solid fraction through a 200μm grid. PCD-S powder was recovered after lyophilization or spray drying of the PCD-S aqueous solutions, eventually followed by a wet granulation step.

Reducing pre-operative fasting while preserving operating room scheduling flexibility: feasibility and impact on patient discomfort.

Background: The need to preserve operating room (OR) scheduling flexibility can challenge adherence to the 2-h pre-operative fasting period recommendation before elective surgery. Our primary objective was to assess the feasibility of a pre-operative carbohydrate (CHO) drink delivery strategy preserving OR scheduling flexibility.

Methods: During the 1st study phase, patients admitted for elective surgery fasted overnight (Control group); during the 2nd phase, patients fasted overnight and received a pre-operative CHO drink (CHO group).

Layer-by-layer coating of textile with two oppositely charged cyclodextrin polyelectrolytes for extended drug delivery.

The coating of a nonwoven textile by polyelectrolyte multilayer film (PEM) issued from cationic and anionic β-cyclodextrin (βCD) polyelectrolytes according to the layer-by-layer (LbL) technique was successfully attempted. The tert-butyl benzoic acid (TBBA) was used as drug model to evaluate the loading capacity and sustained release properties of this PEM system. The build-up of the multilayer assembly was monitored in situ by optical waveguide lightmode spectroscopy (OWLS) on the one hand, and was assessed by gravimetry on the other hand when applied onto the textile substrate.