Wound Dressings Coated with Silver Nanoparticles and Essential Oils for The Management of Wound Infections

Imidazoles and Quaternary Ammonium Compounds as Effective Therapies against (Multidrug-Resistant) Bacterial Wound Infections

BACKGROUND/OBJECTIVES

The rise and spread of antimicrobial resistance complicates the treatment of bacterial wound pathogens, further increasing the need for newer, effective therapies. Azoles such as miconazole have shown promise as antibacterial compounds; however, they are currently only used as antifungals. Previous research has shown that combining azoles with quaternary ammonium compounds yields synergistic activity against fungal pathogens, but the effect on bacterial pathogens has not been studied yet.

METHODS

In this study, the focus was on finding active synergistic combinations of imidazoles and quaternary ammonium compounds against (multidrug-resistant) bacterial pathogens through checkerboard assays. Experimental evolution in liquid culture was used to evaluate the possible emergence of resistance against the most active synergistic combination.

RESULTS

Several promising synergistic combinations were identified against an array of Gram-positive pathogens: miconazole/domiphen bromide, ketoconazole/domiphen bromide, clotrimazole/domiphen bromide, fluconazole/domiphen bromide and miconazole/benzalkonium chloride. Especially, miconazole with domiphen bromide exhibits potential, as it has activity at a low concentration against a broad range of pathogens and shows an absence of strong resistance development over 11 cycles of evolution.

CONCLUSIONS

This study provides valuable insight into the possible combinations of imidazoles and quaternary ammonium compounds that could be repurposed for (topical) wound treatment. Miconazole with domiphen bromide shows the highest application potential as a possible future wound therapy. However, further research is needed into the mode of action of these compounds and their efficacy and toxicity in vivo.

Recent advances in the use of essential oils and their nanoformulations for wound treatment

Despite progress in medical and surgical treatments of wounds, bioactive compounds still offer an effective and safe approach to accelerate wound healing (WH). In this review, recent results of studies on WH by essential oils (EOs) and their terpenoids are reported. Mechanisms of action of these substances and their possible use in drug delivery systems (DDSs) for WH are discussed. EOs of 38 species from 16 families have been evaluated for their potential to treat wounds. Lamiaceae was the most representative family with 10 species, followed by Myrtaceae and Asteraceae. EOs improve WH by acting as anti-inflammatory, antioxidant, and antimicrobial agents. Some other EOs were involved by increasing expression of transforming growth factor (TGF), inhibition of several factors, including plasminogen activator inhibitor-1 (PAI-1), substitution of type III collagen by type I collagen, and up-regulation of insulin-like growth factor-1 (IGF-1), fibroblast growth factor 2 (FGF-2), and vascular endothelial growth factor (VEGF). These mechanisms improved repair of cells and increased proliferation. Alternatively, DDSs based on nanomaterials (NMs) used to carry EOs for WH are mainly based on nanoparticles (NPs), microparticles (MPs) and scaffolds. There is much evidence that EOs can promote WH. Advancement of nanotechnology in recent years has contributed to improving use of EO with DDSs in WH management. However, some limitations need to be addressed to achieve the translation of this technology into clinical applications for wound treatment.

An Overview of Wound Dressing Materials

Wounds are an increasing global concern, mainly due to a sedentary lifestyle, frequently associated with the occidental way of life. The current prevalence of obesity in Western societies, leading to an increase in type II diabetes, and an elderly population, is also a key factor associated with the problem of wound healing. Therefore, it stands essential to find wound dressing systems that allow for reestablishing the skin integrity in the shortest possible time and with the lowest cost, avoiding further damage and promoting patients' well-being. Wounds can be classified into acute or chronic, depending essentially on the duration of the healing process, which is associated withextent and depth of the wound, localization, the level of infection, and the patient's health status. For each kind of wound and respective healing stage, there is a more suitable dressing. The aim of this review was to focus on the possible wound dressing management, aiming for a more adequate healing approach for each kind of wound.

Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

Effective antibacterial agents in modern wound dressings: a review

Wound infections are a significant concern in healthcare, leading to long healing times. Traditional approaches for managing wound infections rely heavily on systemic antibiotics, which are associated with the emergence of antibiotic-resistant bacteria. Therefore, the development of alternative antibacterial materials for wound care has gained considerable attention. In today's world, new generations of wound dressing are commonly used to heal wounds. These new dressings keep the wound and the area around it moist to improve wound healing. However, this moist environment can also foster an environment that is favorable for the growth of bacteria. Excessive antibiotic use poses a significant threat to human health and causes bacterial resistance, so new-generation wound dressings must be designed and developed to reduce the risk of infection. Wound dressings using antimicrobial compounds minimize wound bacterial colonization, making them the best way to avoid open wound infection. We aim to provide readers with a comprehensive understanding of the latest advancements in antibacterial materials for wound management.

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

Complex metal nanostructures represent an exceptional category of materials characterized by distinct morphologies and physicochemical properties. Nanostructures with shape anisotropies, such as nanorods, nanostars, nanocages, and nanoprisms, are particularly appealing due to their tunable surface plasmon resonances, controllable surface chemistries, and effective targeting capabilities. These complex nanostructures can absorb light in the near-infrared, enabling noteworthy applications in nanomedicine, molecular imaging, and biology. The engineering of targeting abilities through surface modifications involving ligands, antibodies, peptides, and other agents potentiates their effects. Recent years have witnessed the development of innovative structures with diverse compositions, expanding their applications in biomedicine. These applications encompass targeted imaging, surface-enhanced Raman spectroscopy, near-infrared II imaging, catalytic therapy, photothermal therapy, and cancer treatment. This review seeks to provide the nanomedicine community with a thorough and informative overview of the evolving landscape of complex metal nanoparticle research, with a specific emphasis on their roles in imaging, cancer therapy, infectious diseases, and biofilm treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Diagnostic Tools > Diagnostic Nanodevices.

Antibacterial efficacy of novel bismuth-silver nanoparticles synthesis on Staphylococcus aureus and Escherichia coli infection models

Introduction

The emergence of multi-drug-resistant bacteria is one of the main concerns in the health sector worldwide. The conventional strategies for treatment and prophylaxis against microbial infections include the use of antibiotics. However, these drugs are failing due to the increasing antimicrobial resistance. The unavailability of effective antibiotics highlights the need to discover effective alternatives to combat bacterial infections. One option is the use of metallic nanoparticles, which are toxic to some microorganisms due to their nanometric size.

Methods

In this study we (1) synthesize and characterize bismuth and silver nanoparticles, (2) evaluate the antibacterial activity of NPs against Staphylococcus aureus and Escherichia coli in several infection models (in vivo models: infected wound and sepsis and in vitro model: mastitis), and we (3) determine the cytotoxic effect on several cell lines representative of the skin tissue.

Results and discussion

We obtained bimetallic nanoparticles of bismuth and silver in a stable aqueous solution from a single reaction by chemical synthesis. These nanoparticles show antibacterial activity on S. aureus and E. coli in vitro without cytotoxic effects on fibroblast, endothelial vascular, and mammary epithelium cell lines. In an infected-wound mice model, antibacterial effect was observed, without effect on in vitro mastitis and sepsis models.

Therapeutic Potential of Nanocarrier-Mediated Delivery of Phytoconstituents for Wound Healing: Their Current Status and Future Perspective

The treatment of wounds is a serious problem all over the world and imposes a huge financial burden on each and every nation. For a long time, researchers have explored wound dressing that speeds up wound healing. Traditional wound dressing does not respond effectively to the wound-healing process as expected. Therapeutic active derived from plant extracts and extracted bioactive components have been employed in various regions of the globe since ancient times for the purpose of illness, prevention, and therapy. About 200 years ago, most medical treatments were based on herbal remedies. Especially in the West, the usage of herbal treatments began to wane in the 1960s as a result of the rise of allopathic medicine. In recent years, however, there has been a resurgence of interest in and demand for herbal medicines for a number of reasons, including claims about their efficacy, shifting consumer preferences toward natural medicines, high costs and negative side effects of modern medicines, and advancements in herbal medicines brought about by scientific research and technological innovation. The exploration of medicinal plants and their typical uses could potentially result in advanced pharmaceuticals that exhibit reduced adverse effects. This review aims to present an overview of the utilization of nanocarriers in plant-based therapeutics, including its current status, recent advancements, challenges, and future prospects. The objective is to equip researchers with a comprehensive understanding of the historical background, current state, and potential future developments in this emerging field. In light of this, the advantages of nanocarriers based delivery of natural wound healing treatments have been discussed, with a focus on nanofibers, nanoparticles, nano-emulsion, and nanogels.

Controlled Size Oils Based Green Fabrication of Silver Nanoparticles for Photocatalytic and Antimicrobial Application

The particle size at the nanometric level allows the manifestation of remarkable properties, chiefly due to changes in surface-to-volume ratio. This study is attributed to the novel green synthesis of nano silver by using essential oils as a capping and reducing agent. Clove oil, cinnamon oil, and cardamom oil were selected for the eco-friendly and low-cost fabrication of silver nanoparticles. The prepared nanoparticles were characterized by photoluminescence spectroscopy, FT-IR spectroscopy, X-Ray diffraction, energy dispersive X-ray spectroscopy, dynamic laser light scattering, thermogravimetric analysis, and transmission electron microscopy. It was found that samples prepared by using cinnamon oil (20 nm) and cardamom oil (12 nm) had smaller particle sizes as compared to those synthesized by using clove oil (45 nm). All the prepared samples exhibited very strong antimicrobial activities with a clear zone of inhibition (6-24 mm) against Staphylococcus aureus, Klebsiella pneumoniae, and Candida albicans. Very resilient photocatalytic activities of the samples were observed against Allura red and fast green dyes. It was concluded that the cinnamon oil-based system is the best size reducer and size homogenizer (less chances of agglomeration) as compared to clove oil and cardamom oil (more chances of agglomeration) for the synthesis of silver nanoparticles.

Why traditional herbal medicine promotes wound healing: Research from immune response, wound microbiome to controlled delivery

Impaired wound healing in chronic wounds has been a significant challenge for clinicians and researchers for decades. Traditional herbal medicine (THM) has a long history of promoting wound healing, making them culturally accepted and trusted by a great number of people in the world. However, for a long time, the understanding of herbal medicine has been limited and incomplete, particularly in the allopathic medicine-dominated research system. The therapeutic effects of individual components isolated from THM are found less pronounced compared to synthetic chemical medicine, and the clinical efficacy is always inferior to herbs. In the present article, we review and discuss underlying mechanisms of the skin microbiome involved in the wound healing process; THM in regulating immune responses and commensal microbiome. We additionally propose few pioneer ideas and studies in the development of therapeutic strategies for controlled delivery of herbal medicine. This review aims to promote wound care with a focus on wound microbiome, immune response, and topical drug delivery systems. Finally, future development trends, challenges, and research directions are discussed.

Oil mediated green synthesis of nano silver in the presence of surfactants for catalytic and food preservation application

The present study details the green synthesis of silver nanoparticles using clove oil as a reducing and stabilizing agent. Cationic, anionic, nonionic and zwitterionic surfactants were introduced to study the change in size, shape, and morphology of nanoparticles. The nanoparticles were characterized using different techniques. The nanoparticles had shown specific surface Plasmon resonance band with absorbance between 380 and 385 nm. The X-ray diffraction study revealed that the nanoparticles are composed of spherical cubic crystals with average size between 136 and 180 nm while Dynamic Laser scattering (DLS) studies revealed an effective diameter of 82 nm and polydispersity index of 0.005. Thermogravimetric analysis suggested that the particles are stable even at 600 °C. All the samples presented good antibacterial and antifungal efficacies against Staphylococcus aureus, Klebsiella pneumonia and Candida albicans and good catalytic activities for the degradation of fast green and Allura red dyes. Further, thin edible films of the nanoparticles were prepared using sodium alginate for food preservation. The films were coated on fruits and vegetables for extending their shelf life to cope with demand and supply gap.

Clove Oil-Incorporated Antibacterial Gelatin-Chitosan Cryogels for Tissue Engineering: An In Vitro Study

Infections are a leading cause of mortality and amputations among patients with burns and chronic wounds, respectively. Moreover, the extensive use of antibiotics has led to the rapid spreading of drug resistance among microorganisms. Alternatively, plant-derived natural products, which have been used as traditional therapies for several centuries, are recently gaining popularity as they are relatively affordable and easily available in many developing countries where modern medications are expensive or unavailable. In this study, clove essential oil is used for its antimicrobial property and is further incorporated into cryogels to increase its bioavailability and prolong its bioactivity. The oil-incorporated cryogels are macroporous, biodegradable, possess mechanical properties similar to commercial skin substitutes, are cytocompatible, antibacterial, and allow long-term sustained release of oil for up to at least 14 days. Additionally, clove oil aids the faster closure of in vitro scratch wounds by improving the migration of fibroblasts. This work presents a novel, bioactive scaffold that has the potential to be used as a dermal substitute and serves as an alternative to commercial skin substitutes.

Advanced drug delivery systems containing herbal components for wound healing

Management of chronic wound has an immense impact on social and economic conditions in the world. Healthcare costs, aging population, physical trauma, and comorbidities of diabetes and obesity seem to be the major factors of this increasing incidence of chronic wounds. Conditions of chronic wound could not restore functional epidermis; thus, delaying the closure of the wound opening in an expected manner. Failures in restoration of skin integrity delay healing due to changes in skin pathology, such as chronic ulceration or nonhealing. The role of different traditional medicines has been explored for use in the healing of cutaneous wounds, where several phytochemicals, such as flavonoids, alkaloids, phenolic acids, tannins are known to provide potential wound healing properties. However, the delivery of plant-based therapeutics could be improved by the novel platform of nanotechnology. Thus, the objectives of novel delivery strategies of principal bioactive from plant sources are to accelerate the wound healing process, avoid wound complications and enhance patient compliance. Therefore, the opportunities of nanotechnology-based drug delivery of natural wound healing therapeutics have been included in the present discussion with special emphasis on nanofibers, vesicular structures, nanoparticles, nanoemulsion, and nanogels.

Bioactive Collagen Hydrolysate-Chitosan/Essential Oil Electrospun Nanofibers Designed for Medical Wound Dressings

In this study, lemon balm (Melissa officinalis L.) and dill (Anethum graveolens L.) essential oils (EOs) were encapsulated into collagen hydrolysates extracted from bovine tendons and rabbit skins, both mixed with chitosan (CS) by using the coaxial electrospinning technique for potential wound dressing applications. The morphology and chemical composition of the electrospun nanofibers were investigated using scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The antimicrobial activity of the dill EO and lemon EO, as well as the electrospun samples loaded with essential oils was determined by disk diffusion assay against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, and Salmonella typhimurium ATCC 14028 bacterial strains; Candida albicans ATCC 10231 and Candida glabrata ATCC 90028 yeast strains; and Aspergillus brasiliensis ATCC 9642 fungal strain. In vivo biocompatibility testing of the collagen hydrolysate-chitosan/essential oil electrospun nanofibers was based on the determination of the hematological, biochemical, and immunological profile and the evaluation of the influence produced on the oxidative stress in white Swiss mice. The synergetic effect of dill and lemon balm EOs can improve the antimicrobial activity of collagen hydrolysate-chitosan nanofibers against the most important bacterial strains. The in vivo test results suggested a good biocompatibility of electrospun samples based on collagen hydrolysate extracted from bovine tendons or rabbit skin mixed with chitosan and containing dill and/or lemon balm essential oils as encapsulated bioactive compounds.

Antibacterial Biodegradable Films Based on Alginate with Silver Nanoparticles and Lemongrass Essential Oil-Innovative Packaging for Cheese

Replacing the petroleum-based materials in the food industry is one of the main objectives of the scientists and decision makers worldwide. Biodegradable packaging will help diminish the environmental impact of human activity. Improving such biodegradable packaging materials by adding antimicrobial activity will not only extend the shelf life of foodstuff, but will also eliminate some health hazards associated with food borne diseases, and by diminishing the food spoilage will decrease the food waste. The objective of this research was to obtain innovative antibacterial films based on a biodegradable polymer, namely alginate. Films were characterized by environmental scanning electron microscopy (ESEM), Fourier-transform infrared spectroscopy (FTIR) and microscopy, complex thermal analysis (TG-DSC-FTIR), UV-Vis and fluorescence spectroscopy. Water vapor permeability and swelling behavior were also determined. As antimicrobial agents, we used silver spherical nanoparticles (Ag NPs) and lemongrass essential oil (LGO), which were found to act in a synergic way. The obtained films exhibited strong antibacterial activity against tested strains, two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Escherichia coli and Salmonella Typhi). Best results were obtained against Bacillus cereus. The tests indicate that the antimicrobial films can be used as packaging, preserving the color, surface texture, and softness of cheese for 14 days. At the same time, the color of the films changed (darkened) as a function of temperature and light presence, a feature that can be used to monitor the storage conditions for sensitive food.

Bioactive Ibuprofen-Loaded PLGA Coatings for Multifunctional Surface Modification of Medical Devices

To modulate the biofunctionality of implantable medical devices commonly used in clinical practice, their surface modification with bioactive polymeric coatings is an attractive and successful emerging strategy. Biodegradable coatings based on poly(lactic acid-co-glycolic acid), PLGA, represent versatile and safe candidates for surface modification of implantable biomaterials and devices, providing additional tunable ability for topical delivery of desired therapeutic agents. In the present study, Ibuprofen-loaded PLGA coatings (PLGA/IBUP) were obtained by using the dip-coating and drop-casting combined protocol. The composite materials demonstrated long-term drug release under biologically simulated dynamic conditions. Reversible swelling phenomena of polymeric coatings occurred in the first two weeks of testing, accompanied by the gradual matrix degradation and slow release of the therapeutic agent. Irreversible degradation of PLGA coatings occurred after one month, due to copolymer's hydrolysis (evidenced by chemical and structural modifications). After 30 days of dynamic testing, the cumulative release of IBUP was ~250 µg/mL. Excellent cytocompatibility was revealed on human-derived macrophages, fibroblasts and keratinocytes. The results herein evidence the promising potential of PLGA/IBUP coatings to be used for surface modification of medical devices, such as metallic implants and wound dressings.

Formulation and Evaluation of a Clove Oil-Encapsulated Nanofiber Formulation for Effective Wound-Healing

Wound-healing is complicated process that is affected by many factors, especially bacterial infiltration at the site and not only the need for the regeneration of damaged tissues but also the requirement for antibacterial, anti-inflammatory, and analgesic activity at the injured site. The objective of the present study was to develop and evaluate the natural essential oil-containing nanofiber (NF) mat with enhanced antibacterial activity, regenerative, non-cytotoxic, and wound-healing potential. Clove essential oil (CEO) encapsulated in chitosan and poly-ethylene oxide (PEO) polymers to form NFs and their morphology was analyzed using scanning electron microscopy (SEM) that confirmed the finest NFs prepared with a diameter of 154 ± 35 nm. The successful incorporation of CEO was characterized by Fourier transform infra-red spectroscopy (FTIR) and X-ray diffractometry (XRD). The 87.6 ± 13.1% encapsulation efficiency and 8.9 ± 0.98% loading of CEO was observed. A total of 79% release of CEO was observed in acidic pH 5.5 with 117% high degree of swelling. The prepared NF mat showed good antibacterial activity against Staphylococcus aureus and Escherichia coli and non-cytotoxic behavior against human fibroblast cell lines and showed good wound-healing potential.

MAPLE Coatings Embedded with Essential Oil-Conjugated Magnetite for Anti-Biofilm Applications

The present study reports on the development and evaluation of nanostructured composite coatings of polylactic acid (PLA) embedded with iron oxide nanoparticles (Fe₃O₄) modified with Eucalyptus (Eucalyptus globulus) essential oil. The co-precipitation method was employed to synthesize the magnetite particles conjugated with Eucalyptus natural antibiotic (Fe₃O₄@EG), while their composition and microstructure were investigated using grazing incidence X-ray diffraction (GIXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The matrix-assisted pulsed laser evaporation (MAPLE) technique was further employed to obtain PLA/Fe₃O₄@EG thin films. Optimal experimental conditions for laser processing were established by complementary infrared microscopy (IRM) and scanning electron microscopy (SEM) investigations. The in vitro biocompatibility with eukaryote cells was proven using mesenchymal stem cells, while the anti-biofilm efficiency of composite PLA/Fe₃O₄@EG coatings was assessed against Gram-negative and Gram-positive pathogens.

Nanotechnology Development for Formulating Essential Oils in Wound Dressing Materials to Promote the Wound-Healing Process: A Review

Wound healing refers to the replacement of damaged tissue through strongly coordinated cellular events. The patient’s condition and different types of wounds complicate the already intricate healing process. Conventional wound dressing materials seem to be insufficient to facilitate and support this mechanism. Nanotechnology could provide the physicochemical properties and specific biological responses needed to promote the healing process. For nanoparticulate dressing design, growing interest has focused on natural biopolymers due to their biocompatibility and good adaptability to technological needs. Polysaccharides are the most common natural biopolymers used for wound-healing materials. In particular, alginate and chitosan polymers exhibit intrinsic antibacterial and anti-inflammatory effects, useful for guaranteeing efficient treatment. Recent studies highlight that several natural plant-derived molecules can influence healing stages. In particular, essential oils show excellent antibacterial, antifungal, antioxidant, and anti-inflammatory properties that can be amplified by combining them with nanotechnological strategies. This review summarizes recent studies concerning essential oils as active secondary compounds in polysaccharide-based wound dressings.

An Updated Review on Silver Nanoparticles in Biomedicine

Silver nanoparticles (AgNPs) represent one of the most explored categories of nanomaterials for new and improved biomaterials and biotechnologies, with impressive use in the pharmaceutical and cosmetic industry, anti-infective therapy and wound care, food and the textile industry. Their extensive and versatile applicability relies on the genuine and easy-tunable properties of nanosilver, including remarkable physicochemical behavior, exceptional antimicrobial efficiency, anti-inflammatory action and antitumor activity. Besides commercially available and clinically safe AgNPs-based products, a substantial number of recent studies assessed the applicability of nanosilver as therapeutic agents in augmented and alternative strategies for cancer therapy, sensing and diagnosis platforms, restorative and regenerative biomaterials. Given the beneficial interactions of AgNPs with living structures and their nontoxic effects on healthy human cells, they represent an accurate candidate for various biomedical products. In the present review, the most important and recent applications of AgNPs in biomedical products and biomedicine are considered.

Recent Trends in Three-Dimensional Bioinks Based on Alginate for Biomedical Applications

Three-dimensional (3D) bioprinting is an appealing and revolutionary manufacturing approach for the accurate placement of biologics, such as living cells and extracellular matrix (ECM) components, in the form of a 3D hierarchical structure to fabricate synthetic multicellular tissues. Many synthetic and natural polymers are applied as cell printing bioinks. One of them, alginate (Alg), is an inexpensive biomaterial that is among the most examined hydrogel materials intended for vascular, cartilage, and bone tissue printing. It has also been studied pertaining to the liver, kidney, and skin, due to its excellent cell response and flexible gelation preparation through divalent ions including calcium. Nevertheless, Alg hydrogels possess certain negative aspects, including weak mechanical characteristics, poor printability, poor structural stability, and poor cell attachment, which may restrict its usage along with the 3D printing approach to prepare artificial tissue. In this review paper, we prepare the accessible materials to be able to encourage and boost new Alg-based bioink formulations with superior characteristics for upcoming purposes in drug delivery systems. Moreover, the major outcomes are discussed, and the outstanding concerns regarding this area and the scope for upcoming examination are outlined.

Development of Hypericum perforatum oil incorporated antimicrobial and antioxidant chitosan cryogel as a wound dressing material

In this study, a herbal infused oil (Hypericum perforatum, HP) incorporated chitosan (CS) cryogel as a wound dressing material was produced in order to be used in wound healing process. The main strategy is to combine the traditional perspective of using medicinal oils with polymeric scaffolds manufactured by an engineering approach to fabricate a potential tissue engineering product that provides both new tissue formation and wound healing. The scaffolds manufactured by cryogelation were soft, spongy, highly porous, physically stable, elastic and could be easily cut in any desired shape. Physicochemical, mechanical and morphological analyzes were used to characterize the produced cryogels. Young modulus of the plain chitosan cryogel was about 21 kPa whereas it increased with increasing HP oil content and became 61 kPa for 20% HP oil ratio. Further, the antimicrobial studies, antioxidant and DNA cleavage effects were investigated. Samples including the highest ratio of oil (CS4) showed the highest DPPH scavenging activity as 69.9%. In addition, 20% HP oil loaded chitosan cryogel demonstrated single strain DNA cleavage activitiy at 500 μg/mL concentration. Antimicrobial studies were applied against seven strains. The lowest activities were obtained against E. hirae and B. cereus, the highest against E. coli and L. pneumophila. This study concluded that the newly developed HP oil loaded chitosan cryogel scaffolds with unique antimicrobial and antioxidant properties are promising candidates to be used in tissue engineering applications as wound dressing for exudative and long-term healing wounds.