Antimicrobial PAA/PAH Electrospun Fiber Containing Green Synthesized Zinc Oxide Nanoparticles for Wound Healing

Electrospun wound dressings with antibacterial function: a critical review of plant extract and essential oil incorporation

Among the many different types of wound dressings, nanofiber-based materials produced through electrospinning are claimed to be ideal because of their advantageous intrinsic properties and the feasibility of employing several strategies to load bioactive compounds into their structure. Bioactive compounds with antimicrobial properties have been incorporated into different wound dressings to promote healing as well as prevent and treat bacterial infections. Among these, natural products, such as medicinal plant extracts and essential oils (EOs), have proven particularly attractive thanks to their nontoxic nature, minor side effects, desirable bioactive properties, and favorable effects on the healing process. To this end, the present review provides an exhaustive and up-to-date revision of the most prominent medicinal plant extracts and EOs with antimicrobial properties that have been incorporated into nanofiber-based wound dressings. The most common methods used for incorporating bioactive compounds into electrospun nanofibers include: pre-electrospinning (blend, encapsulation, coaxial, and emulsion electrospinning), post-electrospinning (physical adsorption, chemical immobilization, and layer-by-layer assembly), and nanoparticle loading. Furthermore, a general overview of the benefits of EOs and medicinal plant extracts is presented, describing their intrinsic properties and biotechniques for their incorporation into wound dressings. Finally, the current challenges and safety issues that need to be adequately clarified and addressed are discussed.

Ultrasonic Coating of Poly(D,L-lactic acid)/Poly(lactic-co-glycolic acid) Electrospun Fibers with ZnO Nanoparticles to Increase Angiogenesis in the CAM Assay

Critical-size bone defects necessitate bone void fillers that should be integrated well and be easily vascularized. One viable option is to use a biocompatible synthetic polymer and sonocoat it with zinc oxide (ZnO) nanoparticles (NPs). However, the ideal NP concentration and size must be assessed because a high dose of ZnO NPs may be toxic. Electrospun PDLLA/PLGA scaffolds were produced with different concentrations (0.5 or 1.0 s of sonocoating) and sizes of ZnO NPs (25 nm and 70 nm). They were characterized by SEM, EDX, ICP-OES, and the water contact angle. Vascularization and integration into the surrounding tissue were assessed with the CAM assay in the living chicken embryo. SEM, EDX, and ICP-OES confirmed the presence of ZnO NPs on polymer fibers. Sonocoated ZnO NPs lowered the WCA compared with the control. Smaller NPs were more pro-angiogenic exhibiting a higher vessel density than the larger NPs. At a lower concentration, less but larger vessels were visible in an environment with a lower cell density. Hence, the favored combination of smaller ZnO NPs at a lower concentration sonocoated on PDLLA/PLGA electrospun meshes leads to an advanced state of tissue integration and vascularization, providing a valuable synthetic bone graft to be used in clinics in the future.

Chitosan-Aloe Vera Composition Loaded with Zinc Oxide Nanoparticles for Wound Healing: In Vitro and In Vivo Evaluations

Global concerns due to the negative impacts of untreatable wounds, as well as the growing population of these patients, emphasize the critical need for advancements in the wound healing materials and techniques. Nanotechnology offers encouraging avenues for improving wound healing process. In this context, nanoparticles (NPs) and certain natural materials, including chitosan (CS) and aloe vera (AV), have demonstrated the potential to promote healing effects. The objective of this investigation is to assess the effect of novel fabricated nanocomposite gel containing CS, AV, and zinc oxide NPs (ZnO NPs) on the wound healing process. The ZnO NPs were synthesized and characterized by X-ray diffraction and electron microscopy. Then, CS/AV gel with different ratios was prepared and loaded with ZnO NPs. The obtained formulations were characterized in vitro based on an antimicrobial study, and the best formulations were used for the animal study to assess their wound healing effects in 21 days. The ZnO NPs were produced with an average 33 nm particle size and exhibited rod shape morphology. Prepared gels were homogenous with good spreadability, and CS/AV/ZnO NPs formulations showed higher antimicrobial effects against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The wound healing findings showed significant wound area reduction in the CS/AV/ZnO NPs group compared to negative control at day 21. Histopathological assessment revealed the advantageous impact of this formulation across various stages of the wound healing process, including collagen deposition (CS/AV/ZnO NPs (2 : 1), 76.6 ± 3.3 compared to negative control, 46.2 ± 3.7) and epitheliogenesis (CS/AV/ZnO NPs (2 : 1), 3 ± 0.9 compared to negative control, 0.8 ± 0.8). CS/AV gel-loaded ZnO NPs showed significant effectiveness in wound healing and would be suggested as a promising formulation in the wound healing process. Further assessments are warranted to ensure the robustness of our findings.

Electrospun organic/inorganic hybrid nanofibers for accelerating wound healing: a review

Electrospun nanofiber membranes hold great promise as scaffolds for tissue reconstruction, mirroring the natural extracellular matrix (ECM) in their structure. However, their limited bioactive functions have hindered their effectiveness in fostering wound healing. Inorganic nanoparticles possess commendable biocompatibility, which can expedite wound healing; nevertheless, deploying them in the particle form presents challenges associated with removal or collection. To capitalize on the strengths of both components, electrospun organic/inorganic hybrid nanofibers (HNFs) have emerged as a groundbreaking solution for accelerating wound healing and maintaining stability throughout the healing process. In this review, we provide an overview of recent advancements in the utilization of HNFs for wound treatment. The review begins by elucidating various fabrication methods for hybrid nanofibers, encompassing direct electrospinning, coaxial electrospinning, and electrospinning with subsequent loading. These techniques facilitate the construction of micro-nano structures and the controlled release of inorganic ions. Subsequently, we delve into the manifold applications of HNFs in promoting the wound regeneration process. These applications encompass hemostasis, antibacterial properties, anti-inflammatory effects, stimulation of cell proliferation, and facilitation of angiogenesis. Finally, we offer insights into the prospective trends in the utilization of hybrid nanofiber-based wound dressings, charting the path forward in this dynamic field of research.

Electrospun Antimicrobial Drug Delivery Systems and Hydrogels Used for Wound Dressings

Wounds and chronic wounds can be caused by bacterial infections and lead to discomfort in patients. To solve this problem, scientists are working to create modern wound dressings with antibacterial additives, mainly because traditional materials cannot meet the general requirements for complex wounds and cannot promote wound healing. This demand is met by material engineering, through which we can create electrospun wound dressings. Electrospun wound dressings, as well as those based on hydrogels with incorporated antibacterial compounds, can meet these requirements. This manuscript reviews recent materials used as wound dressings, discussing their formation, application, and functionalization. The focus is on presenting dressings based on electrospun materials and hydrogels. In contrast, recent advancements in wound care have highlighted the potential of thermoresponsive hydrogels as dynamic and antibacterial wound dressings. These hydrogels contain adaptable polymers that offer targeted drug delivery and show promise in managing various wound types while addressing bacterial infections. In this way, the article is intended to serve as a compendium of knowledge for researchers, medical practitioners, and biomaterials engineers, providing up-to-date information on the state of the art, possibilities of innovative solutions, and potential challenges in the area of materials used in dressings.

Green and eco-friendly biosynthesis of zinc oxide nanoparticles using Calendula officinalis flower extract: Wound healing potential and antioxidant activity

This study aimed to produce zinc oxide nanoparticles with Calendula officinalis flower extract (Co-ZnO NPs) using the green synthesis method. In addition, the antioxidant and wound healing potential of synthesized ZnO NPs were evaluated. The absorbance band at 355 nm, which is typical for ZnO NPs, was determined from the UV-Vis absorbance spectrum. The energy-dispersive X-ray spectroscopy (EDS) measurements revealed a high zinc content of 42.90%. The x-ray diffractometer data showed Co-ZnO NPs with an average crystallite size of 17.66 nm. The Co-ZnO NPs did not have apparent cytotoxicity up to 10 μg/mL (IC50 25.96 μg/mL). C. officinalis ZnO NPs showed partial cell migration and percent wound closure (69.1%) compared with control (64.8%). In addition, antioxidant activities of Co-ZnO NPs with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2 diphenyl-1 picrylhydrazil (DPPH) were evaluated and radical scavenging activity of 33.49% and 46.63%, respectively, was determined. These results suggest that C. officinalis extract is an effective reducing agent for the green synthesis of ZnO NPs with significant antioxidant and wound healing potential.

Sprayed PAA-CaO2 nanoparticles combined with calcium ions and reactive oxygen species for antibacterial and wound healing

The most common socioeconomic healthcare issues in clinical are burns, surgical incisions and other skin injuries. Skin lesion healing can be achieved with nanomedicines and other drug application techniques. This study developed a nano-spray based on cross-linked amorphous calcium peroxide (CaO2) nanoparticles of polyacrylic acid (PAA) for treating skin wounds (PAA-CaO2 nanoparticles). CaO2 serves as a 'drug' precursor, steadily and continuously releasing calcium ions (Ca2+) and hydrogen peroxide (H2O2) under mildly acidic conditions, while PAA-CaO2 nanoparticles exhibited good spray behavior in aqueous form. Tests demonstrated that PAA-CaO2 nanoparticles exhibited low cytotoxicity and allowed L929 cells proliferation and migration in vitro. The effectiveness of PAA-CaO2 nanoparticles in promoting wound healing and inhibiting bacterial growth in vivo was assessed in SD rats using full-thickness skin defect and Staphylococcus aureus (S.aureus)-infected wound models based thereon. The results revealed that PAA-CaO2 nanoparticles demonstrated significant advantages in both aspects. Notably, the infected rats' skin defects healed in 12 days. The benefits are linked to the functional role of Ca2+ coalesces with H2O2 as known antibacterial and healing-promoted agents. Therefore, we developed nanoscale PAA-CaO2 sprays to prevent bacterial development and heal skin lesions.

Recent Progress and Trends in the Development of Electrospun and 3D Printed Polymeric-Based Materials to Overcome Antimicrobial Resistance (AMR)

Antimicrobial resistance (AMR) developed by microorganisms is considered one of the most critical public health issues worldwide. This problem is affecting the lives of millions of people and needs to be addressed promptly. Mainly, antibiotics are the substances that contribute to AMR in various strains of bacteria and other microorganisms, leading to infectious diseases that cannot be effectively treated. To avoid the use of antibiotics and similar drugs, several approaches have gained attention in the fields of materials science and engineering as well as pharmaceutics over the past five years. Our focus lies on the design and manufacture of polymeric-based materials capable of incorporating antimicrobial agents excluding the aforementioned substances. In this sense, two of the emerging techniques for materials fabrication, namely, electrospinning and 3D printing, have gained significant attraction. In this article, we provide a summary of the most important findings that contribute to the development of antimicrobial systems using these technologies to incorporate various types of nanomaterials, organic molecules, or natural compounds with the required property. Furthermore, we discuss and consider the challenges that lie ahead in this research field for the coming years.

Exposure to Zinc Oxide Nanoparticles Increases Estradiol Levels and Induces an Antioxidant Response in Antral Ovarian Follicles In Vitro

The use of zinc oxide nanoparticles (ZnO NP) in consumer products is increasing, raising concern about their potential toxicity to human health. Nanoparticles have endocrine disrupting effects and can induce oxidative stress, leading to biomolecule oxidation and cell dysfunction. The ovary is one of the most important endocrine organs in female reproduction. Nanoparticles accumulate in the ovary, but it is unknown whether and how exposure to these materials disrupts antral follicle functions. Thus, this study tested the hypothesis that the in vitro exposure to ZnO NPs affects the steroidogenic pathway and induces oxidative stress in ovarian antral follicles. Antral follicles from CD-1 mice were cultured with ZnO NPs (5, 10, and 15 µg/mL) for 96 h. ZnO NP exposure did not affect apoptosis and cell cycle regulators at any of the tested concentrations. ZnO NP exposure at low levels (5 µg/mL) increased aromatase levels, leading to increased estradiol levels and decreased estrogen receptor alpha (Esr1) expression. ZnO NP exposure at 15 µg/mL induced an antioxidant response in the antral follicles as evidenced by changes in expression of antioxidant molecules (Nrf2, Cat, Sod1, Gsr, Gpx) and decreased levels of reactive oxygen species. Interestingly, ZnO NPs dissolve up to 50% in media and are internalized in cells as soon as 1 h after culture. In conclusion, ZnO NPs are internalized in antral follicles, leading to increased estrogen production and an antioxidant response.

Wound dressing based on PVA nanofiber containing silk fibroin modified with GO/ZnO nanoparticles for superficial wound healing: In vitro and in vivo evaluations

Silk fibroin (SF), extracted from Bombyx mori, has unique physicochemical properties to achieve an efficient wound dressing. In this study, reduced graphene oxide (RGO)/ZnO NPs/silk fibroin nanocomposite was made, and an innovative nanofiber of SF/polyvinyl alcohol (PVA)/RGO/ZnO NPs was ready with the electrospinning technique and successfully characterized. The results of MIC and OD analyses were used to investigate the synthesized materials' antibacterial effects and displayed that the synthesized materials could inhibit growth against Staphylococcus aureus and Escherichia coli bacteria. However, both in vitro cytotoxicity (MTT) and scratch wound studies have shown that RGO/ZnO NPs and SF/PVA/RGO/ZnO NPs are not only non-toxic to NIH 3T3 fibroblasts, but also can cause cell viability, cell proliferation, and cell migration. Furthermore, improving the synthesized nanofiber's structural properties in the presence of RGO and ZnO NPs has been confirmed by performing tensile strength, contact angle, and biodegradation analyses. Also, in a cell attachment analysis, fibroblast cells had migrated and expanded well in the nanofibrous structures. Moreover, in vivo assay, SF/PVA/RGO/ZnO NPs nanofiber treated rats and has been shown significant healing activity and tissue regeneration compared with other treated groups. Therefore, this study suggests that SF/PVA/RGO/ZnO NPs nanofiber is a hopeful wound dressing for preventing bacteria growth and improving superficial wound repair.

Yerba mate (Ilex paraguariensis A. St.-Hil.) for new therapeutic and nutraceutical interventions: A review of patents issued in the last 20 years (2000-2020)

It has been estimated that more than 70% of all drugs approved worldwide between 1981 and 2006 for human health are derived from or structurally similar to natural compounds. The identification of biological matrices containing bioactive compounds with therapeutic and nutraceutical potential is necessary to supply the global market demands. Researches have indicated that the consumption of dry and aqueous extracts of Ilex paraguariensis A. St.-Hil. is safe, providing that plant biomass does not be exposed to smoke over the drying process, avoiding contamination (e.g., ) with polycyclic aromatic hydrocarbon compounds, and can might help avoiding many diseases, with important potential applications in the pharma and nutraceutical industries. A survey was carried out covering the main therapeutic and nutraceutical studies performed on I. paraguariensis extracts and their relationship with the global patents granted in the last 20 years for the products using this specie in their composition. In the PubMed database, by searching for the term "Ilex paraguariensis," an output with 497 scientific publications was found. Each paper was analyzed individually and 26 publications encompassing exclusively therapeutical and nutraceutical approaches of that plant species were selected. For the patent screening regarding Ilex-derived products, the survey considered three patent databases: European Patent Office (EPO) (Espacenet), World Intellectual Property Organization, WIPO), and National Institute of Industrial Property (NIIP-Brazil). The criterion chosen to select the patents in the databases was the inclusion of the terms "Ilex paraguariensis" and "yerba mate" in the title and/or in the abstract, considering the patents issued from 2000 to 2020. Additionally, only patents with therapeutic and nutraceutical potential were considered on the survey. The screening and selection of the documents were performed independently by two researchers and the information cross-checked at the end. This review contributes to show the state of the art over the last 20 years on the knowledge about the therapeutical and nutraceutical usages of the yerba mate, associated to a certain number of issued patents. The patent survey afforded 62 relevant documents covering products based on Ilex paraguariensis biomass. Considering the number of patents issued, most of them are related to the pharmaceutical area (30), followed by food supplements and beverages (17), cosmetics (10) and, finally, nutraceuticals (5). A detailed analysis of the patents issued showed that most are related to pharmaceutical grade products, generally, marketed as oral and injectable compositions for treatments of obesity, insulin resistance, hyperlipemia and diabetes mellitus, arteriosclerosis, neurological diseases, and SARS-Cov-2, for example. In this work, a curious fact is that there are few patents for food, cosmetics, and nutraceuticals products containing yerba mate. Therefore, it seems to be relevant to take into account the potential of that species as source of bioactive compounds for the development of new products not only intended to the pharma sector. In this sense, 26 reports were identified showing possibilities and trendiness in developing new yerba mate based products, such as packaging, biopesticides, antiseptics, and food supply, expanding the possibilities of technological applications of this plant species.

Recent advances in green synthesized nanoparticles for bactericidal and wound healing applications

Nanotechnology has become an exciting area of research in diverse fields, such as: healthcare, food, agriculture, cosmetics, paints, lubricants, fuel additives and other fields. This review is a novel effort to update the practioneers about the most current developments in the widespread use of green synthesized nanoparticles in medicine. Biosynthesis is widely preferred among different modes of nanoparticle synthesis since they do not require toxic chemical usage and they are environment-friendly. In the green bioprocess, plant, algal, fungal and cyanobacterial extract solutions have been utilized as nucleation/capping agents to develop effective nanomaterials for advanced medical applications. Several metal salts, such as silver, zinc, titanium and other inorganic salts, were utilized to fabricate innovative nanoparticles for healthcare applications. Irrespective of the type of wound, infection in the wound area is a widespread problem. Micro-organisms, the prime reason for wound complications, are gradually gaining resistance against the commonly used antimicrobial drugs. This necessitates the need to generate nanoparticles with efficient antimicrobial potential to keep the pathogenic microbes under control. These nanoparticles can be topically applied as an ointment and also be used by incorporating them into hydrogels, sponges or electrospun nanofibers. The main aim of this review is to highlight the recent advances in the Ag, ZnO and TiO₂ nanoparticles with possible wound healing applications, coupled with the bactericidal ability of a green synthesis process.

An Evaluation of the Biocatalyst for the Synthesis and Application of Zinc Oxide Nanoparticles for Water Remediation—A Review

Global water scarcity is threatening the lives of humans, and it is exacerbated by the contamination of water, which occurs because of increased industrialization and soaring population density. The available conventional physical and chemical water treatment techniques are hazardous to living organisms and are not environmentally friendly, as toxic chemical elements are used during these processes. Nanotechnology has presented a possible way in which to solve these issues by using unique materials with desirable properties. Zinc oxide nanoparticles (ZnO NPs) can be used effectively and efficiently for water treatment, along with other nanotechnologies. Owing to rising concerns regarding the environmental unfriendliness and toxicity of nanomaterials, ZnO NPs have recently been synthesized through biologically available and replenishable sources using a green chemistry or green synthesis protocol. The green-synthesized ZnO NPs are less toxic, more eco-friendly, and more biocompatible than other chemically and physically synthesized materials. In this article, the biogenic synthesis and characterization techniques of ZnO NPs using plants, bacteria, fungi, algae, and biological derivatives are reviewed and discussed. The applications of the biologically prepared ZnO NPs, when used for water treatment, are outlined. Additionally, their mechanisms of action, such as the photocatalytic degradation of dyes, the production of reactive oxygen species (ROS), the generation of compounds such as hydrogen peroxide and superoxide, Zn2+ release to degrade microbes, as well as their adsorbent properties with regard to heavy metals and other contaminants in water bodies, are explained. Furthermore, challenges facing the green synthesis of these nanomaterials are outlined. Future research should focus on how nanomaterials should reach the commercialization stage, and suggestions as to how this ought to be achieved are presented.

Fabrication of Zinc loaded silicon carbide Nanocomposite for in vitro cell viability and in vivo wound dressing care

AIM

In this investigation, Zinc-silicon carbide (Zn-SiC) materials were fabricated by a simple approach by using Zn nanoparticles (Zn-NPs) loaded on silicon carbide (SiC) with enhanced antibacterial and healing activity.

METHODS

Zn-NPs loaded on SiC fabricated by the DIY laser melting technique. The TEM and Zeta-sizer confirmed the morphology and size of the nanoparticles. The characterization was done using Fourier transforms infrared spectroscopy (FTIR), and X-ray diffraction (XRD), Thermogravimetric analysis (TGA). Further, the fabricated nanoparticles were evaluated for their mechanical properties and biocompatibility under storage conditions. In-vivo wound healing was measured by observing a percentage reduction in the wound.

RESULTS

Zn-SiC NPs have 54.6 ± 5.25 nm mean particle size, -15.9 ± 2.35 mV zeta potential with 0.187 ± 0.05 polydispersity index (PD1). The nanoparticles showed good biocompatibility and in-vivo wound healing properties.

CONCLUSIONS

These results strongly support the possibility of using these Zn particles loaded on SiC NPs as a promising wound healing agent after cesarean section.

Nanoparticle-Containing Wound Dressing: Antimicrobial and Healing Effects

The dressings containing nanoparticles of metals and metal oxides are promising types of materials for wound repair. In such dressings, biocompatible and nontoxic hydrophilic polymers are used as a matrix. In the present review, we take a look at the anti-microbial effect of the nanoparticle-modified wound dressings against various microorganisms and evaluate their healing action. A detailed analysis of 31 sources published in 2021 and 2022 was performed. Furthermore, a trend for development of modern antibacterial wound-healing nanomaterials was shown as exemplified in publications starting from 2018. The review may be helpful for researchers working in the areas of biotechnology, medicine, epidemiology, material science and other fields aimed at the improvement of the quality of life.

Functionalized zinc oxide microparticles for improving the antimicrobial effects of skin-care products and wound-care medicines

ZnO is an important component in skin-protection products and wound-care medicines. However, ZnO's antibacterial activity is moderate. We developed two types of ZnO microparticles loading with phthalocyanine-type photosensitizers (ZnO/PSs) introducing the photodynamic effects. These photosensitive ZnO microparticles exhibited long-term while moderate antimicrobial effects by continuously releasing Zn²⁺ ions. The antimicrobial efficacies were remarkably enhanced by triggering the photodynamic antimicrobial effects. Compared to the sole ZnO which showed non-measurable antimicrobial activity at a concentration of 10 mg/L, both ZnO/PSs demonstrated antimicrobial rates ranged 99%-99.99% against Escherichia coli, normal and drug-resistant Staphylococcus aureus. In a dorsal wound infection mouse model, treatment with ZnO/PSs significantly accelerated the wound recovery rates. ZnO/PSs promoted wound healing by a dual effect: 1) the release of Zn²⁺ ions from ZnO facilitating tissue remodeling; 2) the photodynamic effect efficiently eliminates pathogens avoiding infection. Notably, ZnO/PSs inherited the high biosafety of ZnO without causing noticeable toxicity against erythrocyte and endothelial cells. This study not only provides a highly safe and efficient antimicrobial ZnO material for skin cares and wound modulations, but also proposes a strategy to functionalize ZnO materials.

Fabrication of adhesive hydrogels based on poly (acrylic acid) and modified hyaluronic acid

Hydrogel wound dressings with good flexibility and adhesiveness to resist deformation during wound movement are urgently needed in clinical application. In this work, the hydrogels based on poly (acrylic acid) and N-hydroxysuccinimide grafted hyaluronic acid (PAA/HA_-NHS) with good elasticity and adhesiveness were prepared by chemical cross-linking and hydrogen bonding. The elastic and adhesive properties within the PAA hydrogels could reach a balance by adjusting the concentration of potassium persulfate (KPS) and N, N'-methylenebisacrylamide (MBA). Subsequently, HA_-NHS was incorporated into the PAA hydrogel system. The mechanical test revealed that the elongation at break and interfacial toughness of the PAA/HA_-NHS hydrogels could reach 265.79 ± 21.93% and 52.88 ± 3.51 J/m², respectively. In addition, the hydrogels possess a connected porous network and well water absorption ability (with porosity of 51.90 ± 0.11% and swelling ratio in wet state of 122.17 ± 2.78%). In vitro experiment demonstrates that the PAA/HA_-NHS hydrogels exhibit nontoxic and cell in-adhesive properties. The PAA/HA_-NHS hydrogels could cover the wound spots directly, stretch with the skin movement and gently remove from the wound tissue due to the suitable adhesiveness and poor cell adhesion. In conclusion, the PAA/HA_-NHS hydrogels show great application value in the field of wound dressing.