Development of Polyphenol-Functionalized Gelatin-Poly(vinylpyrrolidone) IPN for Potential Biomedical Applications.

Owing to their suitable physical and chemical properties, hydrogels have been considered a convenient choice for wound dressings because of the advantages that they offer, such as maintaining the moist environment required for wound healing. In this research, interpenetrating hydrogels of polyphenol-functionalized gelatin (GE), a water-soluble protein derived from natural polymer collagen with excellent biocompatibility, no immunogenicity, and hydrophilicity, and polyvinylpyrrolidone (PVP), a hydrophilic, non-toxic, biodegradable, biocompatible polymer that is soluble in many solvents, widely used in biomedical applications, particularly as a basic material for the manufacturing of hydrogel wound dressings, were synthesized. Gallic acid (GA) was selected in this work to study whether the interpenetrating polymer networks (IPNs) synthesized can provide antioxidant properties given that this material is intended to be used as a potential wound dressing. The obtained IPN hydrogels showed improved mechanical properties in comparison with pristine gelatin network (net-GE), a porous structure, and good thermal stability for biological applications. The antioxidant capacity of the IPNs functionalized with GA was compared to Trolox standards, obtaining a radical scavenging activity (RSA%) equivalent to a Trolox concentration of 400 µM.

Therapeutic Applications of Terpenes on Inflammatory Diseases.

In the last decades, the search for natural products with biological applications as alternative treatments for several inflammatory diseases has increased. In this respect, terpenes are a family of organic compounds obtained mainly from plants and trees, such as tea, cannabis, thyme, and citrus fruits like lemon or mandarin. These molecules present attractive biological properties such as analgesic and anticonvulsant activities. Furthermore, several studies have demonstrated that certain terpenes could reduce inflammation symptoms by decreasing the release of pro-inflammatory cytokines for example, the nuclear transcription factor-kappa B, interleukin 1, and the tumor necrosis factor-alpha. Thus, due to various anti-inflammatory drugs provoking side effects, the search and analysis of novel therapeutics treatments are attractive. In this review, the analysis of terpenes' chemical structure and their mechanisms in anti-inflammatory functions are addressed. Additionally, we present a general analysis of recent investigations about their applications as an alternative treatment for inflammatory diseases. Furthermore, we focus on terpenes-based nanoformulations and employed dosages to offer a global perspective of the state-of-the-art.

Hyaluronic acid in wound dressings.

Human skin possesses an essential function in the maintenance of individuals' health. However, it may undergo a variety of lesions that produce wounds of distinct severity. In this respect, instantly after any skin wound, the process of tissue regeneration and repair initiates. Nevertheless, diverse factors can delay this process, including bacterial infections, nutritional status, age, hypoxia, chronic diseases, necrosis, and vascular and arterial diseases. Thus, wound dressings are frequently used to improve wound healing. Those wound dressings are fabricated with diverse materials, which confer them different properties. In this regard, hyaluronic acid is a natural polysaccharide widely distributed in extracellular matrices of mammal tissues, which possesses remarkable attributes in terms of biocompatibility, biodegradability, and low cost. Moreover, hyaluronic acid exhibits several beneficial effects on wound healing, such as the decrease of inflammatory processes, regulation of tissue remodeling, and enhancement of angiogenesis. Therefore, in recent years, there is growing attention in this polysaccharide for the design and manufacture of novel wound dressings, which have shown encouraging properties. Here, we describe the different approaches of hyaluronic acid for the production of wound dressings, encompassing hydrogels, films, scaffolds, foams, topical formulations, and nanoformulations, as well as its beneficial effects on wound healing. Finally, we discuss perspectives about the use of hyaluronic acid in wound dressings.

Xanthan gum in drug release.

Controlled release is of vital relevance for many drugs; thus, there is a keen interest in materials that can improve the release profiles of formulations administered via buccal, transdermal, ophthalmic, vaginal, and nasal. The desirable effects of those materials include the improvement of stability, adhesiveness, solubility, and retention time. Hence, different synthetic and natural polymers are utilized to achieve these objectives. In this respect, xanthan gum is an anionic polysaccharide that can be obtained from Xanthomonas bacteria. It is a natural polymer broadly employed in numerous food products, lotions, shampoos, and dermatological articles. Furthermore, due to its physicochemical features, xanthan gum is growingly utilized for the development and improvement of drug delivery systems. In this regard, encouraging findings have been revealed by recent formulations for pharmaceutical applications, including antiviral carriers, antibacterial transporters, transdermal patches, vaginal formulations, and anticancer medications. In this article, we perform a concise description of the chemical properties of xanthan gum and its role as a modifier of drug release. Furthermore, we present an outlook of the state of the art of research focused on the utilization of xanthan gum in varied pharmaceutical formulations, which include tablets, films, hydrogels, and nanoformulations. Finally, we discuss some perspectives about the use of xanthan gum in these formulations.

Recent Advances in Elastin-Based Biomaterial.

Elastin is one of the main components of the extracellular matrix; it provides resistance and elasticity to a variety of tissues and organs of the human body, besides participating in cellular signaling. On the other hand, elastin-derived peptides are synthetic biopolymers with a similar conformation and structure to elastin, but these possess the advantage of solubility in aqueous mediums. Due to their biological activities and physicochemical properties, elastin and related peptides may be applied as biomaterials to develop diverse biomedical devices, including scaffolds, hydrogels, and drug delivery systems for tissue engineering. Likewise, the combination of elastin with natural or synthetic polymers has demonstrated to improve the mechanical properties of biomedical products and drug delivery systems. Here we comprehensively describe the physicochemical properties and physiological functions of elastin. Moreover, we offer an overview of the use of elastin and its derivative polymers as biomaterials to develop scaffolds and hydrogels for tissue engineering. Finally, we discuss some perspectives on the employment of these biopolymers to fabricate new biomedical products.

Fabrication of low-cost micropatterned polydimethyl-siloxane scaffolds to organise cells in a variety of two-dimensioanl biomimetic arrangements for lab-on-chip culture platforms.

We present the rapid-prototyping of type I collagen micropatterns on poly-dimethylsiloxane substrates for the biomimetic confinement of cells using the combination of a surface oxidation treatment and 3-aminopropyl triethoxysilane silanisation followed by glutaraldehyde crosslinking. The aim of surface treatment is to stabilise microcontact printing transfer of this natural extracellular matrix protein that usually wears out easily from poly-dimethylsiloxane, which is not suitable for biomimetic cell culture platforms and lab-on-chip applications. A low-cost CD-DVD laser was used to etch biomimetic micropatterns into acrylic sheets that were in turn replicated to poly-dimethylsiloxane slabs with the desired features. These stamps were finally inked with type I collagen for microcontact printing transfer on the culture substrates in a simple manner. Human hepatoma cells (HepG2) and rat primary hepatocytes, which do not adhere to bare poly-dimethylsiloxane, were successfully seeded and showed optimal adhesion and survival on simple protein micropatterns with a hepatic cord geometry in order to validate our technique. HepG2 cells also proliferated on the stamps. Soft and stiff poly-dimethylsiloxane layers were also tested to demonstrate that our cost-effective process is compatible with biomimetic organ-on-chip technology integrating tunable stiffness with a potential application to drug testing probes development where such cells are commonly used.