Synergistic Effect of Co-Delivering Ciprofloxacin and Tetracycline Hydrochloride for Promoted Wound Healing by Utilizing Coaxial PCL/Gelatin Nanofiber Membrane

Electrospun Gelatin Scaffolds with Incorporated Antibiotics for Skin Wound Healing

Recent advances in regenerative medicine provide encouraging strategies to produce artificial skin substitutes. Gelatin scaffolds are successfully used as wound-dressing materials due to their superior properties, such as biocompatibility and the ability to mimic the extracellular matrix of the surrounding environment. In this study, five gelatin combination solutions were prepared and successfully electrospun using an electrospinning technique. After careful screening, the optimal concentration of the most promising combination was selected for further investigation. The obtained scaffolds were crosslinked with 25% glutaraldehyde vapor and characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The incorporation of antibiotic agents such as ciprofloxacin hydrochloride and gentamicin sulfate into gelatin membranes improved the already existing antibacterial properties of antibiotic-free gelatin scaffolds against Pseudomonas aeruginosa and Staphylococcus aureus. Also, the outcomes from the in vivo model study revealed that skin regeneration was significantly accelerated with gelatin/ciprofloxacin scaffold treatment. Moreover, the gelatin nanofibers were found to strongly promote the neoangiogenic process in the in vivo chick embryo chorioallantoic membrane assay. Finally, the combination of gelatin's extracellular matrix and antibacterial agents in the scaffold suggests its potential for effective wound-healing treatments, emphasizing the importance of gelatin scaffolds in tissue engineering.

Synthesis of biocomposites from microalgal peptide incorporated polycaprolactone/ κ- carrageenan nanofibers and their antibacterial and wound healing property

Antimicrobial peptides (AMPs) are promising novel agents for targeting a wide range of pathogens. In this study, microalgal peptides derived from native microalgae were incorporated into polycaprolactone (PCL) with ƙ-Carrageenan (ƙ-C) forming nanofibers using the electrospinning method. The peptides incorporated in the nanofibers were characterized by fourier infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), and contact angle measurement. The results showed that peptides with molecular weights < 10 kDa, when loaded into nanofibers, exhibited lower wettability. The SEM analysis revealed a thin, smooth, interconnected bead-like structures. The antimicrobial activity of the electrospun nanofibers was evaluated through disc diffusion, and minimum inhibitory activity against Escherichia coli (MTTC 443), and Staphylococcus aureus (MTTC 96), resulting in zones of inhibition of 24 ± 0.5 mm and 14 ± 0.5 mm, respectively. The in vitro biocompatibility of the synthesized nanofibers was confirmed using in HEK 293 cell lines with an increased cell viability. Interestingly, the fibers also exhibited a significant wound-healing properties when used in vitro scratch assays. In conclusion, algal peptides incorporated with PCL/ ƙ-C were found to exhibit antimicrobial and biocompatible biomaterials for wound healing applications.

Adsorption characteristics of ciprofloxacin hydrochloride on polystyrene microplastics in freshwater

In order to reveal the adsorption mechanism of microplastics (MPs) on antibiotics, polystyrene (PS) was chosen as a typical microplastic, Fenton and high-temperature aging methods were used to obtain aged MPs particles. The adsorption behavior and mechanism of ciprofloxacin hydrochloride (CIP) on PS before and after aging were studied by batch adsorption experiments, and other influencing environmental conditions were evaluated concurrently. The results showed that the adsorption of CIP on PS was an exothermic reaction, the pseudo-second-order model and Freundlich isothermal models could fit the adsorption of CIP on PS. Aging treatment enhanced the adsorption capacity of PS to CIP, and Fenton aging for 7 days had the best effect. The highest adsorption was observed when the solution pH was 6. The adsorption capacity of microplastics gradually decreased with increasing ionic strength and the concentration of fulvic acid, while the aging microplastics changed little with the concentration of fulvic acid. The presence of both Cu (II) and CIP inhibits the adsorption of each other on microplastics. Based on the above findings, the adsorption of CIP on PS is dominated by physical adsorption, and electrostatic interactions and hydrogen bonding interactions are also important mechanisms for the adsorption of CIP on microplastics.

Catecholamines polymerization crosslinking for alginate-based burn wound dressings developed with ciprofloxacin and zinc oxide interactions

There is an increasing demand for stable and durable wound dressings to treat burn injuries and infections. Bioactive electrospun nanofibrous mats with antibacterial properties are promising for wound dressing usage. Electrospinning of biopolymers for wound dressing applications needs post-spinning crosslinking to prevent mat dissolution in moist wound environments. Here, we prepared durable wound dressing by using the Dopamine (DA) polymerization crosslinking in Alginate (ALG)/Polyvinyl alcohol (PVA) nanofibrous mats, which are developed by Ciprofloxacin (CIP) and Zinc oxide (ZO). The nanofibrous mats were investigated by FESEM, FTIR, mechanical strength, water contact angle, degradation, degree of swelling, and WVTR tests. The analyses demonstrate the nanofibrous mats with uniform and unbranched fibers, with a hydrophilic nature, which was porous, durable, and stable. Also, it showed the CIP and ZO addition enhanced their durability by crosslinking reinforcement. In addition, the drug release and antibacterial assays demonstrated the pH-sensitive release with more drug release at higher pH (bacterial invasion) and impressive antibacterial activity (up to 99 %). In the burn wound model in rats, the ALG/PVA/DA/CIP/ZO nanofibrous mats displayed excellent wound healing ability in wound closure and tissue regeneration. Also, complete re-epithelization and remodeling and highest collagen synthesis in histological assessment.

Electrospun multi-chamber core-shell nanofibers and their controlled release behaviors: A review

Core-shell structure is a concentric circle structure found in nature. The rapid development of electrospinning technology provides more approaches for the production of core-shell nanofibers. The nanoscale effects and expansive specific surface area of core-shell nanofibers can facilitate the dissolution of drugs. By employing ingenious structural designs and judicious polymer selection, specialized nanofiber drug delivery systems can be prepared to achieve controlled drug release. The synergistic combination of core-shell structure and materials exhibits a strong strategy for enhancing the drug utilization efficiency and customizing the release profile of drugs. Consequently, multi-chamber core-shell nanofibers hold great promise for highly efficient disease treatment. However, little attention concentration is focused on the effect of multi-chamber core-shell nanofibers on controlled release of drugs. In this review, we introduced different fabrication techniques for multi-chamber core-shell nanostructures, including advanced electrospinning technologies and surface functionalization. Subsequently, we reviewed the different controlled drug release behaviors of multi-chamber core-shell nanofibers and their potential needs for disease treatment. The comprehensive elucidation of controlled release behaviors based on electrospun multi-chamber core-shell nanostructures could inspire the exploration of novel controlled delivery systems. Furthermore, once these fibers with customizable drug release profiles move toward industrial mass production, they will potentially promote the development of pharmacy and the treatment of various diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Accelerating Full-Thickness Wound Healing with Bacterial Cellulose-Based Multilayer Composites

Materials that speed up wound healing can be of great benefit to patients and healthcare providers. One-layer dressings, however, have unsatisfactory healing efficacy since it is impossible to use materials with different properties simultaneously, and drug delivery is limited by the depth of penetration. The present study utilized a multilayer wound dressing composed of bacterial cellulose (BC) hydrogel, gelatin/alginate (Gel/Alg) hydrogel, and polycaprolactone (PCL) nanofibers loaded with ciprofloxacin (CIP) to promote the healing process in vivo. The designed dressings showed significant water absorption and sufficient water vapor transmission rate (WVTR) after one week, confirming their ability to absorb wound exudate. Within the first four hours, significant amounts of CIP were released from the drug-containing dressing. Then, between hours 4 and 24, the rate decreased and plateaued on day 9. Both positive and negative bacterial strains were inhibited by the gradual release of CIP, while fibroblasts retained their normal morphology and metabolic activity. Lastly, in vivo tests demonstrated that CIP-loaded multilayer dressings could significantly speed up full-thickness wound healing during 14 days, by reducing inflammation, stimulating re-epithelialization, and enhancing skin regeneration. Our findings indicate that multilayering BC hydrogels with drug-loaded nanofibers provide a promising way to promote wound healing by utilizing all the distinctive properties of these layers.

Ciprofloxacin- and levofloxacin-loaded nanoparticles efficiently suppressed fluoroquinolone resistance and biofilm formation in Acinetobacter baumannii

The spread of fluoroquinolone (FQ) resistance in Acinetobacter baumannii represents a critical health threat. This study aims to overcome FQ resistance in A. baumannii via the formulation of polymeric nanoFQs. Herein, 80 A. baumannii isolates were obtained from diverse clinical sources. All A. baumannii isolates showed high resistance to most of the investigated antimicrobials, including ciprofloxacin (CIP) and levofloxacin (LEV) (97.5%). FQ resistance-determining regions of the gyrA and parC genes were the most predominant resistant mechanism, harbored by 69 (86.3%) and 75 (93.8%) of the isolates, respectively. Additionally, plasmid-mediated quinolone resistance genes aac(6')-Ib and qnrS were detected in 61 (76.3%) and 2 (2.5%) of the 80 isolates, respectively. The CIP- and LEV-loaded poly ε-caprolactone (PCL) nanoparticles, FCIP and FLEV, respectively, showed a 1.5-6- and 6-12-fold decrease in the MIC, respectively, against the tested isolates. Interestingly, the time kill assay demonstrated that MICs of FCIP and FLEV completely killed A. baumannii isolates after 5-6 h of treatment. Furthermore, FCIP and FLEV were found to be efficient in overcoming the FQ resistance mediated by the efflux pumps in A. baumannii isolates as revealed by decreasing the MIC four-fold lower than that of free CIP and LEV, respectively. Moreover, FCIP and FLEV at 1/2 and 1/4 MIC significantly decreased biofilm formation by 47-93% and 69-91%, respectively. These findings suggest that polymeric nanoparticles can restore the effectiveness of FQs and represent a paradigm shift in the fight against A. baumannii isolates.

Wound Dressing Scaffold with High Anti-biofilm Performance Based on Ciprofloxacin-Loaded Chitosan-Hydrolyzed Starch Nanocomposite: In Vitro and In Vivo Study

Today, the search for solutions to reduce wound infection and restore wound receptivity also reduces its side effects which are a difficult problem in medical science research. The greatest options for this purpose are hydrogel dressings since they are compatible with tissue and have an antibacterial effect on wound healing. Chronic wounds represent a significant burden on people and healthcare systems worldwide. Bacteria often enter such skin wounds, causing irritation and complicating the healing process. In addition, bacteria cause infection, which inhibits rejuvenation and the production of collagen. This study is aimed at developing novel chitosan (CS)-hydrolyzed starch nanocomposite (HS/Ch-NC) loaded with ciprofloxacin to enhance its skin retention and wound healing efficacy and anti-biofilm efficacy. Drug-loading on the (HS/Ch-NC) and encapsulation efficiency was 55.2% and 97.2%, respectively. The activity of HS-NC loaded with ciprofloxacin as anti-biofilm activity by 72% and 63% against Enterobacter aerogenes and Pseudomonas aeruginosa, respectively. The obtained (HS/Ch-NC) loaded with ciprofloxacin is a promising candidate for the development of improved bandage materials, as cell viability and proliferation was assessed using an SRB assay with half-maximal inhibitory concentrations (IC50) at 119.1 µg/ml. In vitro scratch wound healing assay revealed significant (p ≤ 0.05) acceleration in wound closure at 24 h enhanced by 56.04% 24-h and 100% 72-h post-exposure to (HS/Ch-NC) loaded ciprofloxacin, compared to the negative control. In vivo skin retention study revealed that (HS/Ch-NC)-loaded ciprofloxacin showed 3.65-fold higher retention, respectively, than ciprofloxacin. Thus, our study assumes that ciprofloxacin-loaded HS-NC is a potential delivery system for enhancing ciprofloxacin skin retention and wound healing activity.

Creation of Chitosan-Based Nanocapsule-in-Nanofiber Structures for Hydrophobic/Hydrophilic Drug Co-Delivery and Their Dressing Applications in Diabetic Wounds

Nanofiber meshes (NFMs) loaded with therapeutic agents are very often employed to treat hard-to-heal wounds such as diabetic wounds. However, most of the NFMs have limited capability to load multiple or hydrophilicity distinctive-therapeutic agents. The therapy strategy is therefore significantly hampered. To tackle the innate drawback associated with the drug loading versatility, a chitosan-based nanocapsule-in-nanofiber (NC-in-NF) structural NFM system is developed for simultaneous loading of hydrophobic and hydrophilic drugs. Oleic acid-modified chitosan is first converted into NCs by the developed mini-emulsion interfacial cross-linking procedure, followed by loading a hydrophobic anti-inflammatory agent Curcumin (Cur) into the NCs. Sequentially, the Cur-loaded NCs are successfully introduced into reductant-responsive maleoyl functional chitosan/polyvinyl alcohol NFMs containing a hydrophilic antibiotic Tetracycline hydrochloride. Having a co-loading capability for hydrophilicity distinctive agents, biocompatibility, and a controlled release property, the resulting NFMs have demonstrated the efficacy on promoting wound healing either in normal or diabetic rats.

Regeneration and modification of cellulose acetate from cigarette waste: Biomedical potential by encapsulation of tetracycline hydrochloride

Cigarette waste are pervasive litter on Earth, posing a major threat to organisms and ecosystems. However, these waste contain cellulose acetate (CA) and can be recycled, transforming into raw materials for new products. Polymers like CA can be used in biomedical applications as drug carriers and scaffolds for drug release. In this study, cigarette filters waste was collected, recycled and used for fabricating the nanofibrous membrane of cellulose acetate nanofibers (CFCA) through electrospinning technique. Tetracycline hydrochloride (TC) was encapsulated in the nanofibers to prevent bacterial infections. Various analyses were conducted: Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction Analysis (XRD) and Thermogravimetric analysis (TGA). CA and CFCA exhibited high water uptake properties and exhibited similar breaking stress and strain values. Both CA and CFCA effectively acted as stable drug carriers, with sustained in vitro drug release. Antibacterial activity was demonstrated by the drug-loaded CA and CFCA nanofibers against, Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. Based on their cytotoxicity evaluations on mouse fibroblast cells (L929), CA and CFCA fibrous mats demonstrated no cytotoxicity and similar cell viability results. Consequently, the TC-loaded nanofibers made from CA and CFCA exhibited suitable properties for wound healing applications.

Drug Loaded 3D-Printed Poly(ε-Caprolactone) Scaffolds for Local Antibacterial or Anti-Inflammatory Treatment in Bone Regeneration

Annual bone grafting surgeries due to bone fractures, resections of affected bones, skeletal anomalies, osteoporosis, etc. exceed two million worldwide. In this regard, the creation of new materials for bone tissue repair is one of the urgent tasks of modern medicine. Additive manufacturing, or 3D printing, offers great opportunities for the development of materials with diverse properties and designs. In this study, the one-pot technique for the production of 3D scaffolds based on poly(ε-caprolactone) (PCL) loaded with an antibiotic or anti-inflammatory drug was proposed. In contrast to previously described methods to prepare drug-containing scaffolds, drug-loaded PCL scaffolds were prepared by direct 3D printing from a polymer/drug blend. An investigation of the mechanical properties of 3D-printed scaffolds containing 0.5-5 wt% ciprofloxacin (CIP) or dexamethasone (DEX) showed almost no effect of the drug (compression modulus ~70-90 MPa) compared to unfilled PCL (74 MPa). At the same time, introducing the drug and increasing its content in the PCL matrix contributed to a 1.8-6.8-fold decrease in the specific surface area of the scaffold, depending on composition. The release of CIP and DEX in phosphate buffer solution and in the same buffer containing lipase revealed a faster release in enzyme-containing medium within 45 days. Furthermore, drug release was more intensive from scaffolds with a low drug load. Analysis of the release profiles using a number of mathematical dissolution models led to the conclusion that diffusion dominates over other probable factors. In vitro biological evaluation of the scaffolds containing DEX showed moderate toxicity against osteoblast-like and leukemia monocytic cells. Being 3D-printed together with PCL both drugs retain their biological activity. PCL/CIP and PCL/DEX scaffolds demonstrated antibacterial properties against Pseudomonas aeruginosa (a total inhibition after 48 h) and anti-inflammatory activity in experiments on TNFα-activated monocyte cells (a 4-time reduction in CD-54 expression relative to control), respectively.

Electrospun Nanofiber Membranes with Various Structures for Wound Dressing

Electrospun nanofiber membranes (NFMs) have high porosity and a large specific surface area, which provide a suitable environment for the complex and dynamic wound healing process and a large number of sites for carrying wound healing factors. Further, the design of the nanofiber structure can imitate the structure of the human dermis, similar to the natural extracellular matrix, which better promotes the hemostasis, anti-inflammatory and healing of wounds. Therefore, it has been widely studied in the field of wound dressing. This review article overviews the development of electrospinning technology and the application of electrospun nanofibers in wound dressings. It begins with an introduction to the history, working principles, and transformation of electrospinning, with a focus on the selection of electrospun nanofiber materials, incorporation of functional therapeutic factors, and structural design of nanofibers and nanofiber membranes. Moreover, the wide application of electrospun NFMs containing therapeutic factors in wound healing is classified based on their special functions, such as hemostasis, antibacterial and cell proliferation promotion. This article also highlights the structural design of electrospun nanofibers in wound dressing, including porous structures, bead structures, core-shell structures, ordered structures, and multilayer nanofiber membrane structures. Finally, their advantages and limitations are discussed, and the challenges faced in their application for wound dressings are analyzed to promote further research in this field.

Phytoconstituent-Loaded Nanofibrous Meshes as Wound Dressings: A Concise Review

In the past, wounds were treated with natural materials, but modern wound dressings include functional elements to expedite the process of healing and to improve skin recovery. Due to their exceptional properties, nanofibrous wound dressings are now the most cutting-edge and desirable option. Similar in structure to the skin’s own extracellular matrix (ECM), these dressings can promote tissue regeneration, wound fluid transportation, and air ductility for cellular proliferation and regeneration owing to their nanostructured fibrous meshes or scaffolds. Many academic search engines and databases, such as Google Scholar, PubMed, and Sciencedirect, were used to conduct a comprehensive evaluation of the literature for the purposes of this investigation. Using the term “nanofibrous meshes” as a keyword, this paper focuses on the importance of phytoconstituents. This review article summarizes the most recent developments and conclusions from studies on bioactive nanofibrous wound dressings infused with medicinal plants. Several wound-healing methods, wound-dressing materials, and wound-healing components derived from medicinal plants were also discussed.

Overview of Antimicrobial Biodegradable Polyester-Based Formulations

As the clinical complications induced by microbial infections are known to have life-threatening side effects, conventional anti-infective therapy is necessary, but not sufficient to overcome these issues. Some of their limitations are connected to drug-related inefficiency or resistance and pathogen-related adaptive modifications. Therefore, there is an urgent need for advanced antimicrobials and antimicrobial devices. A challenging, yet successful route has been the development of new biostatic or biocide agents and biomaterials by considering the indisputable advantages of biopolymers. Polymers are attractive materials due to their physical and chemical properties, such as compositional and structural versatility, tunable reactivity, solubility and degradability, and mechanical and chemical tunability, together with their intrinsic biocompatibility and bioactivity, thus enabling the fabrication of effective pharmacologically active antimicrobial formulations. Besides representing protective or potentiating carriers for conventional drugs, biopolymers possess an impressive ability for conjugation or functionalization. These aspects are key for avoiding malicious side effects or providing targeted and triggered drug delivery (specific and selective cellular targeting), and generally to define their pharmacological efficacy. Moreover, biopolymers can be processed in different forms (particles, fibers, films, membranes, or scaffolds), which prove excellent candidates for modern anti-infective applications. This review contains an overview of antimicrobial polyester-based formulations, centered around the effect of the dimensionality over the properties of the material and the effect of the production route or post-processing actions.

PCL/Gelatin/Graphene Oxide Electrospun Nanofibers: Effect of Surface Functionalization on In Vitro and Antibacterial Response

The emergence of resistance to pathogenic bacteria has resulted from the misuse of antibiotics used in wound treatment. Therefore, nanomaterial-based agents can be used to overcome these limitations. In this study, polycaprolactone (PCL)/gelatin/graphene oxide electrospun nanofibers (PGO) are functionalized via plasma treatment with the monomeric groups diallylamine (PGO-M1), acrylic acid (PGO-M2), and tert-butyl acrylate (PGO-M3) to enhance the action against bacteria cells. The surface functionalization influences the morphology, surface wettability, mechanical properties, and thermal stability of PGO nanofibers. PGO-M1 and PGO-M2 exhibit good antibacterial activity against Staphylococcus aureus and Escherichia coli, whereas PGO-M3 tends to reduce their antibacterial properties compared to PGO nanofibers. The highest proportion of dead bacteria cells is found on the surface of hydrophilic PGO-M1, whereas live cells are colonized on the surface of hydrophobic PGO-M3. Likewise, PGO-M1 shows a good interaction with L929, which is confirmed by the high levels of adhesion and proliferation with respect to the control. All the results confirm that surface functionalization can be strategically used as a tool to engineer PGO nanofibers with controlled antibacterial properties for the fabrication of highly versatile devices suitable for different applications (e.g., health, environmental pollution).

Amphotericin B- and Levofloxacin-Loaded Chitosan Films for Potential Use in Antimicrobial Wound Dressings: Analytical Method Development and Its Application

Levofloxacin (LVX) and amphotericin B (AMB) have been widely used to treat bacterial and fungal infections in the clinic. Herein, we report, for the first time, chitosan films loaded with AMB and LVX as wound dressings to combat antimicrobial infections. Additionally, we developed and validated a high-performance liquid chromatography (HPLC) method coupled with a UV detector to simultaneously quantify both AMB and LVX. The method is easy, precise, accurate and linear for both drugs at a concentration range of 0.7-5 µg/mL. The validated method was used to analyse the drug release, ex vivo deposition and permeation from the chitosan films. LVX was released completely from the chitosan film after a week, while approximately 60% of the AMB was released. Ex vivo deposition study revealed that, after 24-hour application, 20.96 ± 13.54 µg of LVX and approximately 0.35 ± 0.04 µg of AMB was deposited in porcine skin. Approximately 0.58 ± 0.16 µg of LVX permeated through the skin. AMB was undetectable in the receptor compartment due to its poor solubility and permeability. Furthermore, chitosan films loaded with AMB and LVX were found to be able to inhibit the growth of both Candida albicans and Staphylococcus aureus, indicating their potential for antimicrobial applications.

A Refined Hot Melt Printing Technique with Real-Time CT Imaging Capability

Personalised drug delivery systems with the ability to offer real-time imaging and control release are an advancement in diagnostic and therapeutic applications. This allows for a tailored drug dosage specific to the patient with a release profile that offers the optimum therapeutic effect. Coupling this application with medical imaging capabilities, real-time contrast can be viewed to display the interaction with the host. Current approaches towards such novelty produce a drug burst release profile and contrasting agents associated with side effects as a result of poor encapsulation of these components. In this study, a 3D-printed drug delivery matrix with real-time imaging is engineered. Polycaprolactone (PCL) forms the bulk structure and encapsulates tetracycline hydrochloride (TH), an antibiotic drug and Iron Oxide Nanoparticles (IONP, Fe₃O₄), a superparamagnetic contrasting agent. Hot melt extrusion (HME) coupled with fused deposition modelling (FDM) is utilised to promote the encapsulation of TH and IONP. The effect of additives on the formation of micropores (10-20 µm) on the 3D-printed surface was investigated. The high-resolution process demonstrated successful encapsulation of both bioactive and nano components to present promising applications in drug delivery systems, medical imaging and targeted therapy.

Hybrid-Based Wound Dressings: Combination of Synthetic and Biopolymers

Most commercialized wound dressings are polymer-based. Synthetic and natural polymers have been utilized widely for the development of wound dressings. However, the use of natural polymers is limited by their poor mechanical properties, resulting in their combination with synthetic polymers and other materials to enhance their mechanical properties. Natural polymers are mostly affordable, biocompatible, and biodegradable with promising antimicrobial activity. They have been further tailored into unique hybrid wound dressings when combined with synthetic polymers and selected biomaterials. Some important features required in an ideal wound dressing include the capability to prevent bacteria invasion, reduce odor, absorb exudates, be comfortable, facilitate easy application and removal as well as frequent changing, prevent further skin tear and irritation when applied or removed, and provide a moist environment and soothing effect, be permeable to gases, etc. The efficacy of polymers in the design of wound dressings cannot be overemphasized. This review article reports the efficacy of wound dressings prepared from a combination of synthetic and natural polymers.

Tuning the Drug Release from Antibacterial Polycaprolactone/Rifampicin-Based Core-Shell Electrospun Membranes: A Proof of Concept

The employment of coaxial fibers for guided tissue regeneration can be extremely advantageous since they allow the functionalization with bioactive compounds to be preserved and released with a long-term efficacy. Antibacterial coaxial membranes based on poly-ε-caprolactone (PCL) and rifampicin (Rif) were synthesized here, by analyzing the effects of loading the drug within the core or on the shell layer with respect to non-coaxial matrices. The membranes were, therefore, characterized for their surface properties in addition to analyzing drug release, antibacterial efficacy, and biocompatibility. The results showed that the lower drug surface density in coaxial fibers hinders the interaction with serum proteins, resulting in a hydrophobic behavior compared to non-coaxial mats. The air-plasma treatment increased their hydrophilicity, although it induced rifampicin degradation. Moreover, the substantially lower release of coaxial fibers influenced the antibacterial efficacy, tested against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Indeed, the coaxial matrices were inhibitory and bactericidal only against S. aureus, while the higher release from non-coaxial mats rendered them active even against E. coli. The biocompatibility of the released rifampicin was assessed too on murine fibroblasts, revealing no cytotoxic effects. Hence, the presented coaxial system should be further optimized to tune the drug release according to the antibacterial effectiveness.

Progress in Gelatin as Biomaterial for Tissue Engineering

Tissue engineering has become a medical alternative in this society with an ever-increasing lifespan. Advances in the areas of technology and biomaterials have facilitated the use of engineered constructs for medical issues. This review discusses on-going concerns and the latest developments in a widely employed biomaterial in the field of tissue engineering: gelatin. Emerging techniques including 3D bioprinting and gelatin functionalization have demonstrated better mimicking of native tissue by reinforcing gelatin-based systems, among others. This breakthrough facilitates, on the one hand, the manufacturing process when it comes to practicality and cost-effectiveness, which plays a key role in the transition towards clinical application. On the other hand, it can be concluded that gelatin could be considered as one of the promising biomaterials in future trends, in which the focus might be on the detection and diagnosis of diseases rather than treatment.

Antibacterial Vancomycin@ZIF-8 Loaded PVA Nanofiber Membrane for Infected Bone Repair

Bone substitutes with strong antibacterial properties and bone regeneration effects have an inherent potential in the treatment of severe bone tissue infections, such as osteomyelitis. In this study, vancomycin (Van) was loaded into zeolitic imidazolate framework-8 (ZIF-8) to prepare composite particles, which is abbreviated as V@Z. As a pH-responsive particle, ZIF-8 can be cleaved in the weak acid environment caused by bacterial infection to realize the effective release of drugs. Then, V@Z was loaded into polyvinyl alcohol (PVA) fiber by electrospinning to prepare PVA/V@Z composite bone filler. The drug-loading rate of V@Z was about 6.735%. The membranes exhibited super hydrophilicity, water absorption and pH-controlled Van release behavior. The properties of anti E. coli and S. aureus were studied under the pH conditions of normal physiological tissues and infected tissues (pH 7.4 and pH 6.5, respectively). It was found that the material had good surface antibacterial adhesion and antibacterial property. The PVA/V@Z membrane had the more prominent bacteria-killing effect compared with the same amount of single antibacterial agent containing membrane such as ZIF-8 or Van loaded PVA, and the antibacterial rate was up to 99%. The electrospun membrane had good biocompatibility and can promote MC3T3-E1 cell spreading on it.