Incorporation of antimicrobial peptides on functionalized cotton gauzes for medical applications

Asymmetric Superhydrophobic/Superhydrophilic Cotton Fabrics Designed by Spraying Polymer and Nanoparticles

Inspired by the special wettability of certain natural life forms, such as the high water repellency of lotus leaves, many researchers have attempted to impart superhydrophobic properties to fabrics in academic and industrial contexts. Recently, a new switching system of wettability has inspired a strong demand for advanced coatings, even though their fabrication remains complex and costly. Here, cotton fabrics with asymmetric wettability (one face with natural superhydrophilicity and one face with superhydrophobicity) were fabricated by one-step spraying of a mixture of biocompatible commercial materials, hydrophobic SiO2 nanoparticles and ethyl-α-cyanoacrylate superglue. Our approach involves controlling the permeation of the fabric coatings by changing the distance between the fabric and the sprayer, to make one side superhydrophobic and the other side naturally superhydrophilic. As a result, the superhydrophobic side, with its high mechanical durability, exhibited a water contact angle of 154° and sliding angle of 16°, which meets the requirement for self-cleaning ability of surfaces. The opposite side exhibited high water absorption ability owing to the natural superhydrophilic property of the fabric. In addition, the designed cotton fabrics had blood absorption and clotting abilities on the superhydrophilic side, while the superhydrophobic side prevented water and blood permeation without losing the natural breathability of the cotton. These functions may be useful in the design of multifunctional fabrics for medical applications.

Polyelectrolyte Multilayers: A Versatile Tool for Preparing Antimicrobial Coatings

The prevention of pathogen colonization of medical implants represents a major medical and financial issue. The development of antimicrobial coatings aimed at protecting against such infections has thus become a major field of scientific and technological research. Three main strategies are developed to design such coatings: (i) the prevention of microorganisms adhesion and the killing of microorganisms (ii) by contact and (iii) by the release of active compounds in the vicinity of the implant. Polyelectrolyte multilayer (PEM) technology alone covers the entire widespread spectrum of functionalization possibilities. PEMs are obtained through the alternating deposition of polyanions and polycations on a substrate, and the great advantages of PEMs are that (i) they can be applied to almost any type of substrate whatever its shape and composition; (ii) various chemical, physicochemical, and mechanical properties of the coatings can be obtained; and (iii) active compounds can be embedded and released in a controlled manner. In this article we will give an overview of the field of PEMs applied to the design of antimicrobial coatings, illustrating the large versatility of the PEM technology.

Advanced Therapeutic Dressings for Effective Wound Healing--A Review

Advanced therapeutic dressings that take active part in wound healing to achieve rapid and complete healing of chronic wounds is of current research interest. There is a desire for novel strategies to achieve expeditious wound healing because of the enormous financial burden worldwide. This paper reviews the current state of wound healing and wound management products, with emphasis on the demand for more advanced forms of wound therapy and some of the current challenges and driving forces behind this demand. The paper reviews information mainly from peer-reviewed literature and other publicly available sources such as the US FDA. A major focus is the treatment of chronic wounds including amputations, diabetic and leg ulcers, pressure sores, and surgical and traumatic wounds (e.g., accidents and burns) where patient immunity is low and the risk of infections and complications are high. The main dressings include medicated moist dressings, tissue-engineered substitutes, biomaterials-based biological dressings, biological and naturally derived dressings, medicated sutures, and various combinations of the above classes. Finally, the review briefly discusses possible prospects of advanced wound healing including some of the emerging physical approaches such as hyperbaric oxygen, negative pressure wound therapy and laser wound healing, in routine clinical care.

Metal-Based Antibacterial Substrates for Biomedical Applications

The interest in nanotechnology and the growing concern for the antibiotic resistance demonstrated by many microorganisms have recently stimulated many efforts in designing innovative biomaterials and substrates with antibacterial properties. Among the implemented strategies to control the incidence of infections associated with the use of biomedical device and implants, interesting routes are represented by the incorporation of bactericidal agents onto the surface of biomaterials for the prevention of bacterial adhesion and biofilm growth. Natural products and particularly bioactive metals such as silver, copper and zinc represent an interesting alternative for the development of advanced biomaterials with antimicrobial properties. This review presents an overview of recent progress in the modification of biomaterials as well as the most attractive techniques for the deposition of antimicrobial coatings on different substrates for biomedical application. Moreover, some research activities and results achieved by the authors in the development of antibacterial materials are also presented and discussed.