Polymer-Based Hydrogel Loaded with Honey in Drug Delivery System for Wound Healing Applications.

Excellent wound dressings should have crucial components, including high porosity, non-toxicity, high water absorption, and the ability to retain a humid environment in the wound area and facilitate wound healing. Unfortunately, current wound dressings hamper the healing process, with poor antibacterial, anti-inflammatory, and antioxidant activity, frequent dressing changes, low biodegradability, and poor mechanical properties. Hydrogels are crosslinked polymer chains with three-dimensional (3D) networks that have been applicable as wound dressings. They could retain a humid environment on the wound site, provide a protective barrier against pathogenic infections, and provide pain relief. Hydrogel can be obtained from natural, synthetic, or hybrid polymers. Honey is a natural substance that has demonstrated several therapeutic efficacies, including anti-inflammatory, antibacterial, and antioxidant activity, which makes it beneficial for wound treatment. Honey-based hydrogel wound dressings demonstrated excellent characteristics, including good biodegradability and biocompatibility, stimulated cell proliferation and reepithelization, inhibited bacterial growth, and accelerated wound healing. This review aimed to demonstrate the potential of honey-based hydrogel in wound healing applications and complement the studies accessible regarding implementing honey-based hydrogel dressing for wound healing.

Transcriptomic Profile Analysis of Streptococcus mutans Response to Acmella paniculata Flower Extracts.

Background: Acmella paniculata has been used as a traditional medicine to treat oral health diseases such as dental caries and periodontitis. Streptococcus mutans is a common bacterium that initiates dental caries at an early stage. Aim: The aim of this study was to determine the mode of action of A. paniculata (extracts) against S. mutans growth. Methods: Time-kill assay has been done to investigate the rate of kill and effectiveness of Acmella paniculata (AP) extracts against S. mutans growth. Phytochemical analysis was done to identify major compounds in AP extracts using gas chromatography mass spectrometry (GCMS). Scanning and transmission electron microscopy (SEM and TEM) have been done to observe the morphological changes of treated bacteria. Transcriptomic profile analysis has been done using Next Gene Sequencing. Results: AP flower n-hexane (APFH) and AP flower dichloromethane (APFD) extracts acted as bactericidal agents after killing >3 log10 cfu/mL of S. mutans after 24 hours. Oleic and hexadecenoic acids were found to be the major compounds in APFD and APFH extracts, respectively. Photomicrographs from SEM and TEM of treated S. mutans show that the bacterial cell wall has been lysed and the cytoplasm content was decreased. Pathway analysis revealed that the APFD extract significantly affected biosynthesis peptidoglycan, gene expression, RNA processing, and macromolecule metabolism processes in S. mutans. Conclusion: Data analysis revealed that multiple mechanisms of action were involved in antibacterial activity of A. paniculata extracts toward S. mutans.

An Overview of siRNA Delivery Strategies for Urological Cancers.

The treatment of urological cancers has been significantly improved in recent years. However, for the advanced stages of these cancers and/or for those developing resistance, novel therapeutic options need to be developed. Among the innovative strategies, the use of small interfering RNA (siRNA) seems to be of great therapeutic interest. siRNAs are double-stranded RNA molecules which can specifically target virtually any mRNA of pathological genes. For this reason, siRNAs have a great therapeutic potential for human diseases including urological cancers. However, the fragile nature of siRNAs in the biological environment imposes the development of appropriate delivery systems to protect them. Thus, ensuring siRNA reaches its deep tissue target while maintaining structural and functional integrity represents one of the major challenges. To reach this goal, siRNA-based therapies require the development of fine, tailor-made delivery systems. Polymeric nanoparticles, lipid nanoparticles, nanobubbles and magnetic nanoparticles are among nano-delivery systems studied recently to meet this demand. In this review, after an introduction about the main features of urological tumors, we describe siRNA characteristics together with representative delivery systems developed for urology applications; the examples reported are subdivided on the basis of the different delivery materials and on the different urological cancers.

The remarkable three-dimensional network structure of bacterial cellulose for tissue engineering applications.

Cellulose is a natural homopolymer, composed of ß-1,4- anhydro-d-glucopyranose units. Unlike plant cellulose, bacterial cellulose (BC), obtained from species belonging to the genera of Acetobacter, Rhizobium, Agrobacterium, and Sarcina through various cultivation methods and techniques, is produced in its pure form. BC is produced in the form of gel-like, never dry sheet with tremendous mechanical properties. Containing up to 99% of water, BC hydrogel is considered biocompatible thus finding robust applications in the health industry. Moreover, BC three-dimensional structure closely resembles the extracellular matrix (ECM) of living tissue. In this review, we focus on the porous BC morphology particularly suited to host oxygen and nutrients thus providing conducive environment for cell growth and proliferation. The remarkable BC porous morphology makes this biological material a promising templet for the generation of 3D tissue culture and possibly for tissue-engineered scaffolds.

Antibacterial drug release from a biphasic gel system: Mathematical modelling.

Bacterial infections represent an important drawback in the orthopaedic field, as they can develop either immediately after surgery procedures or after some years. Specifically, in case of implants, they are alleged to be troublesome as their elimination often compels a surgical removal of the infected implant. A possible solution strategy could involve a local coating of the implant by an antibacterial system, which requires to be easily applicable, biocompatible and able to provide the desired release kinetics for the selected antibacterial drug. Thus, this work focusses on a biphasic system made up by a thermo-reversible gel matrix (Poloxamer 407/water system) hosting a dispersed phase (PLGA micro-particles), containing a model antibacterial drug (vancomycin hydrochloride). In order to understand the key parameters ruling the performance of this delivery system, we developed a mathematical model able to discriminate the drug diffusion inside micro-particles and within the gel phase, eventually providing to predict the drug release kinetics. The model reliability was confirmed by fitting to experimental data, proposing as a powerful theoretical approach to design and optimize such in situ delivery systems.

Potential Applications of Nanocellulose-Containing Materials in the Biomedical Field.

Because of its high biocompatibility, bio-degradability, low-cost and easy availability, cellulose finds application in disparate areas of research. Here we focus our attention on the most recent and attractive potential applications of cellulose in the biomedical field. We first describe the chemical/structural composition of cellulose fibers, the cellulose sources/features and cellulose chemical modifications employed to improve its properties. We then move to the description of cellulose potential applications in biomedicine. In this field, cellulose is most considered in recent research in the form of nano-sized particle, i.e., nanofiber cellulose (NFC) or cellulose nanocrystal (CNC). NFC is obtained from cellulose via chemical and mechanical methods. CNC can be obtained from macroscopic or microscopic forms of cellulose following strong acid hydrolysis. NFC and CNC are used for several reasons including the mechanical properties, the extended surface area and the low toxicity. Here we present some potential applications of nano-sized cellulose in the fields of wound healing, bone-cartilage regeneration, dental application and different human diseases including cancer. To witness the close proximity of nano-sized cellulose to the practical biomedical use, examples of recent clinical trials are also reported. Altogether, the described examples strongly support the enormous application potential of nano-sized cellulose in the biomedical field.