Tina Maver

Novel cellulose based materials for safe and efficient wound treatment.

The present study aims at achieving effects of improved hydrophilicity and microorganism inhibition, which are rarely simultaneously present in wound dressings. Viscose fibers in their non-woven form were modified using two different pathways. Effects of a two-step procedure, i.e. alkaline or oxygen plasma treatment followed by the attachment of silver chloride nanoparticles were compared to a one-step procedure, i.e. ammonium plasma treatment, which results in both desired material characteristics simultaneously. The surface properties of untreated and differently modified cellulose samples were analyzed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), in vitro silver release, and hydrophilicity measurements. The treatment effect on antimicrobial activity was determined by the AATCC 100-1999 standard test. In light of the introduced wound dressing preparation procedures and the desired wound dressing characteristics, the effectiveness of the used procedures was evaluated. Antimicrobial activity was proven against all Gram negative bacteria, while the Gram positive bacteria survive the as-prepared samples. Hydrophilicity was proven to be excellent using both preparation procedures. The mentioned results prove the potential of the used procedures and encourage future developments toward the clinical proof of concept.

Functional wound dressing materials with highly tunable drug release properties

Wound dressings, capable of local controlled delivery of non-steroid anti-inflammatory pain-killing drugs (NSAIDs) to the wound bed, offer great potential to accelerate wound healing, hence increase the quality of patient life. With local NSAID delivery, unwanted side effects encountered in their systemic delivery, are drastically diminished. In this study, four functional fibrous wound dressing materials, namely viscose, alginate, sodium carboxymethyl cellulose (Na-CMC) and polyethylene terephthalate (PET) loaded with a NSAID, diclofenac sodium (DCF) are prepared, and their suitability to tune the release rate of DCF is evaluated. Through careful examination of material–drug combinations, in terms of their physicochemical properties (air permeability, wettability and water retention) and structural/morphological properties (infrared spectroscopy, wide angle X-ray scattering and scanning electron microscopy), possible wound care applications are proposed. In vitro release studies using an automated Franz diffusion cell system, combined with UV-Vis absorption spectroscopy for drug release profile determination, are performed as the final pre-formulation test. Results showed significant differences in the release profiles between different material–drug combinations, making the examined materials highly applicable for several wound care applications. The present study presents a novel cost effective approach for preparation of drug loaded wound dressing materials without a sacrifice in patient safety. Additionally, novel methods and material–drug combinations are introduced, paving the way for possible future wound treatment options.

A review of herbal medicines in wound healing

Herbs have been integral to both traditional and non‐traditional forms of medicine dating back at least 5000 years. The enduring popularity of herbal medicines may be explained by the perception that herbs cause minimal unwanted side effects. More recently, scientists increasingly rely on modern scientific methods and evidence‐based medicine to prove efficacy of herbal medicines and focus on better understanding of mechanisms of their action. However, information concerning quantitative human health benefits of herbal medicines is still rare or dispersed, limiting their proper valuation. Preparations from traditional medicinal plants are often used for wound healing purposes covering a broad area of different skin‐related diseases. Herbal medicines in wound management involve disinfection, debridement, and provision of a suitable environment for aiding the natural course of healing. Here we report on 22 plants used as wound healing agents in traditional medicine around the world. The aim of this review is therefore to review herbal medicines, which pose great potential for effective treatment of minor wounds.

Modification of cellulose non-woven substrates for preparation of modern wound dressings

Different ways are presented of modifying cellulosic non-woven substrates, which can serve as potential wound dressings with satisfactory antimicrobial and hydrophilic properties. For safe attachment of silver particles without a measurable release from the used materials, a sol–gel derived process was used. Alkaline and oxygen plasma treatments were used to improve the hydrophilicity of the materials. Their efficiency was determined by measuring contact angles and water retention values. Scanning electron microscopy (SEM) was used for determination of sample morphology prior to and after treatment. The efficiency of silver attachment and activity was evaluated by in vitro release studies and antimicrobial tests. Atomic force microscopy (AFM) and SEM, combined with dynamic light scattering, were used for determination of silver particle size. Additionally, we evaluated the influence of treatment on technological parameters, important for application performance, i.e. mechanical properties and air permeability.

Electrospun nanofibrous CMC/PEO as a part of an effective pain-relieving wound dressing

Abstract A novel two-layered pain-relieving wound dressing was prepared from a combination of biocompatible polymers: carboxymethylcellulose and polyethyleneoxide, and two types of pain-relieving drugs: the non-steroid anti-inflammatory diclofenac and the local anesthetic lidocaine. To achieve the two-layered structure, electrospinning and impregnation of a commercially available wound dressing Aquacel® were used for preparation of respective layers. The electrospun nanofibers have been shown to possess similar features as found in the extracellular matrix, an important component of the skin. This characteristic could significantly contribute to the efficiency of wound healing. The second layer is based on Aquacel®, an important wound dressing in modern wound care. Since pain can drastically lower the wound healing process, as well as it is known to decrease the overall quality of patient life, pain-relieving drugs are very interesting for wound care applications. For efficient pain reduction, two types of drugs were used. When combined, these can cover different types of wound-related pain (due to the cause and treatment) and hence additionally aid the wound healing process. The combined features of the incorporated pain-relieving drugs and the mentioned materials are therefore very interesting for future studies toward clinical testing of possible prototype products.Graphical Abstract

Layering of different materials to achieve optimal conditions for treatment of painful wounds

Despite a range of advanced wound dressings that can facilitate wound healing, there are still no clinically used dressings for effective local pain management. The latter was the main motivation of the present study. We designed a novel wound dressing with three layers. A macro-porous polyethylene terephthalate (PET) mesh with incorporated lidocaine, a fast-acting local anesthetic, was chosen as the layer in direct contact with the skin. Fast release from this layer enables an immediate pain relieving effect, caused by dressing changes. For the second and third layer, alginate and viscose were chosen respectively. A potential long-lasting pain relieving effect was achieved through incorporation of a nonsteroidal anti-inflammatory drug diclofenac into both layers. The chosen dressing structure enables also an unhindered absorption of the wound exudate, which is possible through the macro-porous PET into the alginate layer. Alginate additionally maintains a moist wound environment. Our novel wound dressing was systematically tested in regard of the structural (contact angle measurements, IR spectroscopy, SEM), functional (water retention, air permeability) properties and its biocompatibility (Live/Dead and MTT assays) towards human skin fibroblasts. Combined results confirmed the suitability of the chosen wound dressing composition for a faster and painless wound treatment.

Advanced therapies of skin injuries

SummaryThe loss of tissue is still one of the most challenging problems in healthcare. Efficient laboratory expansion of skin tissue to reproduce the skins barrier function can make the difference between life and death for patients with extensive full-thickness burns, chronic wounds, or genetic disorders such as bullous conditions. This engineering has been initiated based on the acute need in the 1980s and today, tissue-engineered skin is the reality. The human skin equivalents are available not only as models for permeation and toxicity screening, but are frequently applied in vivo as clinical skin substitutes. This review aims to introduce the most important recent development in the extensive field of tissue engineering and to describe already approved, commercially available skin substitutes in clinical use.

Polymer Characterization with the Atomic Force Microscope

Atomic force microscopy is a powerful characterization tool for polymer science, capable of revealing surface structures with superior spatial resolution [1]. The universal character of repulsive forces between the tip and the sample, which are employed for surface analysis in AFM, enables examination of even single polymer molecules without disturbance of their integrity [2]. Being initially developed as the analogue of scanning tunneling microscopy (STM) for the high-resolution profiling of non-conducting surfaces, AFM has developed into a multifunctional technique suitable for characterization of topography, adhesion, mechanical, and other properties on scales from tens of microns to nanometers [3].

Combining 3D printing and electrospinning for preparation of pain-relieving wound-dressing materials

AbstractPain is already known to cause delays in wound healing. Therefore, providing suitable therapeutic solutions for less painful wound healing should attract significantly more attention in the development of future novel wound care solutions. In this study, the nonsteroidal anti-inflammatory drug (NSAID) diclofenac sodium (DCS) and the local anesthetic lidocaine (LID) were combined in wound-dressing materials prepared using two different techniques. We compared the release of the mentioned drugs from a 3D bioprinted carboxymethyl cellulose (CMC)-based scaffold with their release from an electrospun CMC-based nano-mesh. As a well-defined and controlled drug release is of great importance for any material to be used in the clinics, we have put a lot of effort into a systematic evaluation of both prepared materials, using the two different techniques. For this purpose, we used different methods to characterize their physico–chemical, structural and morphological properties. Further, the influence of the respective preparation procedures were tested on the release profile and biocompatibility with human skin cells. Both prepared materials were proven biocompatible. We have also shown that the drug release of both incorporated drugs was affected significantly by the preparation method. The resulting release performances of the respective materials were shown to benefit the treatment of specific wounds. Finally, several advantageous properties could be achieved by combining both preparation techniques for the preparation of a single dressing.

Advanced Wound Care

The world is ageing rapidly. The percentage of older people (aged 60 years and over) worldwide increased from 9.2 % in 1990 to 11.7 % in 2013, and will reach 21.1 % by 2050 (Wound Management in An