A novel bacterial biofilms eradication strategy based on the microneedles with antibacterial properties

Biofilm Battle: New transformative tactics to tackle the bacterial biofilm infections

Bacterial biofilm infections are the root cause of persistent infections and the prevalence of resistance to specific or multiple antibiotics. Biofilms have unique features that provide a protective environment for bacteria under various stress conditions and contribute significantly to the pathogenesis of chronic infections. They cover bacterial cells with a self-produced extracellular polymeric matrix, effectively hiding the bacterial cells and their targets. Conventional therapies cannot effectively treat and control bacterial biofilm infections. Therefore, advanced therapeutic means like microneedles, targeted tissue therapy, phage therapy, nanodrug therapy, combination drug therapy, microbial therapy, and immune cell hijacking therapy are needed to tackle the complex issue. These advanced therapies have shown promising results not only in bacterial biofilm infections but also in diseases such as cancer and genetic disorders. Due to their unique features and mechanisms, they significantly contribute to preventing bacterial infections by disrupting biofilm. This article aims to serve as a comprehensive overview of the ongoing battle against biofilms with transformative therapies. This article compiles advancements in new therapies that have demonstrated effective roles in the disruption of bacterial biofilms. We also discuss the current developments and Food and Drug Administration-approved status of these therapies. Additionally, this article summarizes the limitations and future steps needed for these therapies in the field of bacterial biofilm prevention. Thus, these therapies represent the future of preventing bacterial biofilm infections and could be also effective in the reversal of resistance.

Nanozyme-Incorporated Microneedles for the Treatment of Chronic Wounds

Acute wounds are converted to chronic wounds due to advanced age and diabetic complications. Nanozymes catalyze ROS production to kill bacteria without causing drug resistance, while microneedles (MNs) can break through the skin barrier to deliver drugs effectively. Nanozymes can be intergrateded into MNs delivery systems to improve painless drug delivery. It can also reduce the effective dose of drug sterilization while increasing delivery efficiency and effectively killing wounded bacteria while preventing drug resistance. This paper describes various types of metal nanozymes from previous studies and compares their mutual enhancement with nanozymes. The pooled results show that the MNs, through material innovation, are able to both penetrate the scab and deliver nanozymes and exert additional anti-inflammatory and bactericidal effects. The catalytic effect of some of the nanozymes can also accelerate the lysis of the MNs or create a cascade reaction against inflammation and infection. However, the issue of increased toxicity associated with skin penetration and clinical translation remains a challenge. This study reviews the latest published results and corresponding challenges associated with the use of MNs combined with nanozymes for the treatment of wounds, providing further information for future research.

Nanoparticle-Based Strategies for Managing Biofilm Infections in Wounds: A Comprehensive Review

Chronic wounds containing opportunistic bacterial pathogens are a growing problem, as they are the primary cause of morbidity and mortality in developing and developed nations. Bacteria can adhere to almost every surface, forming architecturally complex communities called biofilms that are tolerant to an individual's immune response and traditional treatments. Wound dressings are a primary source and potential treatment avenue for biofilm infections, and research has recently focused on using nanoparticles with antimicrobial activity for infection control. This Review categorizes nanoparticle-based approaches into four main types, each leveraging unique mechanisms against biofilms. Metallic nanoparticles, such as silver and copper, show promising data due to their ability to disrupt bacterial cell membranes and induce oxidative stress, although their effectiveness can vary based on particle size and composition. Phototherapy-based nanoparticles, utilizing either photodynamic or photothermal therapy, offer targeted microbial destruction by generating reactive oxygen species or localized heat, respectively. However, their efficacy depends on the presence of light and oxygen, potentially limiting their use in deeper or more shielded biofilms. Nanoparticles designed to disrupt extracellular polymeric substances directly target the biofilm structure, enhancing the penetration and efficacy of antimicrobial agents. Lastly, nanoparticles that induce biofilm dispersion represent a novel strategy, aiming to weaken the biofilm's defense and restore susceptibility to antimicrobials. While each method has its advantages, the selection of an appropriate nanoparticle-based treatment depends on the specific requirements of the wound environment and the type of biofilm involved. The integration of these nanoparticles into wound dressings not only promises enhanced treatment outcomes but also offers a reduction in the overall use of antibiotics, aligning with the urgent need for innovative solutions in the fight against antibiotic-tolerant infections. The overarching objective of employing these diverse nanoparticle strategies is to replace antibiotics or substantially reduce their required dosages, providing promising avenues for biofilm infection management.

Integration of polysaccharide electrospun nanofibers with microneedle arrays promotes wound regeneration: A review

Utilizing electrospun nanofibers and microneedle arrays in wound regeneration has been practiced for several years. Researchers have recently asserted that using multiple methods concurrently might enhance efficiency, despite the inherent strengths and weaknesses of each individual approach. The combination of microneedle arrays with electrospun nanofibers has the potential to create a drug delivery system and wound healing method that offer improved efficiency and accuracy in targeting. The use of microneedles with nanofibers allows for precise administration of pharmaceuticals due to the microneedles' capacity to pierce the skin and the nanofibers' role as a drug reservoir, resulting in a progressive release of drugs over a certain period of time. Electrospun nanofibers have the ability to imitate the extracellular matrix and provide a framework for cellular growth and tissue rejuvenation, while microneedle arrays show potential for enhancing tissue regeneration and enhancing the efficacy of wound healing. The integration of electrospun nanofibers with microneedle arrays may be customized to effectively tackle particular obstacles in the fields of wound healing and drug delivery. However, some issues must be addressed before this paradigm may be fully integrated into clinical settings, including but not limited to ensuring the safety and sterilization of these products for transdermal use, optimizing manufacturing methods and characterization of developed products, larger-scale production, optimizing storage conditions, and evaluating the inclusion of multiple therapeutic and antimicrobial agents to increase the synergistic effects in the wound healing process. This research examines the combination of microneedle arrays with electrospun nanofibers to enhance the delivery of drugs and promote wound healing. It explores various kinds of microneedle arrays, the materials and processes used, and current developments in their integration with electrospun nanofibers.

Synergistic effect of doxycycline and aqueous extract of irradiated khella on structure of nanobacteria isolated from kidney stones: In vitro and in vivo studies

Kidney stones have been associated with an increased risk of chronic kidney diseases, end-stage renal failure. This study is devoted to isolate nanobacteria from patients with active urolithiasis and investigate the in vitro and in vivo antinanobacterial activity of some antibiotics alone or in combination with extracts of irradiated herbs from certain medicinal plants. Nanobacteria were detected using scanning (SEM) and transmission (TEM) electron microscopy, protein electrophoresis (SDS-PAGE) and DNA profile. The antimicrobial susceptibility of some biofilm-producing nanobacterial isolates was evaluated. The effect of medicinal plant extracts on growth was tested. A combination treatment between the most potent extracts and antibiotics was tested on biofilm production, protein profile, release of 260 nm absorbing material, protein content, and ultrastructure of the strongest biofilm producers. In vivo study of nanobacteria and its treatment by the most potent agents was evaluated on male rats. Renal function was measured in serum; histological examination and oxidative stress parameters were determined in kidney tissues. Results showed that streptomycin, trimethoprim/sulfamethoxazole, doxycycline, and water extracts of irradiated khella at 6 kGy had antinanobacterial activity. Meanwhile, the synergistic effect of the aqueous extract of irradiated Khella and doxycycline showed higher inhibition activity on microbial growth and biofilm production. They affected dramatically the strength of its cell membrane and subsequently its ultrastructure. Moreover, these results are confirmed by ameliorations in renal function and histological alterations. It could be concluded that the combination of DO and an aqueous extract of irradiated khella has an antinephrotoxic effect against nanobacteria-induced renal toxicity.

Chitosan-based microneedle arrays for dermal delivery of Centella Asiatica

Centella asiatica, a medicinal herb used for wound healing, has a limited effect when delivered as an ointment. Centella asiatica's active component asiatic acid (AA) increases extracellular matrix development and reduces inflammation but cannot penetrate the stratum corneum to access deeper skin layers. To bypass the stratum corneum, we formulated two types of AA-loaded microneedle arrays. We fabricated, characterised and optimised a dissolving array made from chitosan and PVA and a hydrogel array made from chitosan and PVP. Both needles were strong and long enough to pierce the epidermis without breaking. Both were biocompatible with keratinocytes and fibroblasts (>75% viability at 100% concentration) and showed a sustained drug release over 48 hours. The hydrogel microneedle released more AA (52.2%) than the dissolving formulation (26.4%); thus, we evaluated them in an excisional rat model. The hydrogel microneedle arrays significantly increased the rate of wound closure compared to the control. This research has shown that the chitosan-PVA hydrogel microneedles could penetrate the epidermis, effectively release AA, and increase the wound closure rate. This AA-loaded delivery system shows promise as a natural treatment for wound healing and may be applied to other bioactive compounds with similar physiochemical properties in the future.

Advancements in Skin Delivery of Natural Bioactive Products for Wound Management: A Brief Review of Two Decades

Application of modern delivery techniques to natural bioactive products improves their permeability, bioavailability, and therapeutic efficacy. Many natural products have desirable biological properties applicable to wound healing but are limited by their inability to cross the stratum corneum to access the wound. Over the past two decades, modern systems such as microneedles, lipid-based vesicles, hydrogels, composite dressings, and responsive formulations have been applied to natural products such as curcumin or aloe vera to improve their delivery and efficacy. This article reviews which natural products and techniques have been formulated together in the past two decades and the success of these applications for wound healing. Many cultures prefer natural-product-based traditional therapies which are often cheaper and more available than their synthetic counterparts. Improving natural products’ effect can provide novel wound-healing therapies for those who trust traditional compounds over synthetic drugs to reduce medical inequalities.

An Overview on the Recent Advances in the Treatment of Infected Wounds: Antibacterial Wound Dressings

A wound can be surgical, cuts from an operation or due to accident and trauma. The infected wound, as a result of bacteria growth within the damaged skin, interrupts the natural wound healing process and significantly impacts the quality of life. Wound dressing is an important segment of the skincare industry with its economic burden estimated at $ 20.4 billion (in 2021) in the global market. The results of recent clinical trials suggest that the use of modern dressings can be the easiest, most accessible, and most cost-effective way to treat chronic wounds and, hence, holds significant promise. With the sheer number of dressings in the market, the selection of correct dressing is confusing for clinicians and healthcare workers. The aim of this research was to review widely used types of antibacterial wound dressings, as well as emerging products, for their efficiency and mode of action. In this review, we focus on introducing antibiotics and antibacterial nanoparticles as two important and clinically widely used categories of antibacterial agents. The perspectives and challenges for paving the way for future research in this field are also discussed. This article is protected by copyright. All rights reserved.

The Expanded Role of Chitosan in Localized Antimicrobial Therapy

Chitosan is one of the most studied natural origin polymers for biomedical applications. This review focuses on the potential of chitosan in localized antimicrobial therapy to address the challenges of current rising antimicrobial resistance. Due to its mucoadhesiveness, chitosan offers the opportunity to prolong the formulation residence time at mucosal sites; its wound healing properties open possibilities to utilize chitosan as wound dressings with multitargeted activities and more. We provide an unbiased overview of the state-of-the-art chitosan-based delivery systems categorized by the administration site, addressing the site-related challenges and evaluating the representative formulations. Specifically, we offer an in-depth analysis of the current challenges of the chitosan-based novel delivery systems for skin and vaginal infections, including its formulations optimizations and limitations. A brief overview of chitosan's potential in treating ocular, buccal and dental, and nasal infections is included. We close the review with remarks on toxicity issues and remaining challenges and perspectives.

Therapy of infected wounds: overcoming clinical challenges by advanced drug delivery systems

In recent years, the incidence of infected wounds is steadily increasing, and so is the clinical as well as economic interest in effective therapies. These combine reduction of pathogen load in the wound with general wound management to facilitate the healing process. The success of current therapies is challenged by harsh conditions in the wound microenvironment, chronicity, and biofilm formation, thus impeding adequate concentrations of active antimicrobials at the site of infection. Inadequate dosing accuracy of systemically and topically applied antibiotics is prone to promote development of antibiotic resistance, while in the case of antiseptics, cytotoxicity is a major problem. Advanced drug delivery systems have the potential to enable the tailor-made application of antimicrobials to the side of action, resulting in an effective treatment with negligible side effects. This review provides a comprehensive overview of the current state of treatment options for the therapy of infected wounds. In this context, a special focus is set on delivery systems for antimicrobials ranging from semi-solid and liquid formulations over wound dressings to more advanced carriers such as nano-sized particulate systems, vesicular systems, electrospun fibers, and microneedles, which are discussed regarding their potential for effective therapy of wound infections. Further, established and novel models and analytical techniques for preclinical testing are introduced and a future perspective is provided.

Chitosan-based microneedles as a potential platform for drug delivery through the skin: Trends and regulatory aspects

Microneedles (MNs) fabrication using chitosan has gained significant interest due to its ability of film-forming, biodegradability, and biocompatibility, making it suitable for topical and transdermal drug delivery. The presence of amine and hydroxyl functional groups on chitosan permits the modification with tunable properties and functionalities. In this regard, chitosan is the preferred material for fabrication of MNs because it does not produce an immune response in the body and can be tailored as per required strength and functionalities. Therefore, many researchers have attempted to use chitosan as a drug delivery vehicle for hydrophilic drugs, peptides, and hormones. In 2020, the FDA has issued "Regulatory Considerations for Microneedling Products". This official guidance is a sign for future opportunities in the development of MNs. The present review focuses on properties, and modifications of chitosan used in the fabrication of MNs. The therapeutic and diagnostic applications of different types of chitosan-based MNs have been discussed. Further, the regulatory aspects of MN-based devices, and patents related to chitosan-based MNs are discussed.

Microneedle arrays for the treatment of chronic wounds

INTRODUCTION

Chronic wounds are seen frequently in diabetic and bedbound patients. Such skin injuries, which do not heal in a timely fashion, can lead to life-threatening conditions. In an effort to resolve the burdens of chronic wounds, numerous investigations have explored the efficacy of various therapeutics on wound healing. Therapeutics can be topically delivered to cutaneous wounds to reduce the complications associated with systemic drug delivery because the compromised skin barrier is not expected to negatively affect drug distribution. However, researchers have recently demonstrated that the complex environment of chronic wounds could lower the localized availability of the applied therapeutics. Microneedle arrays (MNAs) can be exploited to enhance delivery efficiency and consequently improved healing.

AREAS COVERED

In this review, we briefly describe the pathophysiology of chronic wounds and current treatment strategies. We further introduce methods and materials commonly used for the fabrication of MNAs. Subsequently, the studies demonstrating the benefits of MNAs in wound care are highlighted.

EXPERT OPINION

Microneedles have great potential to treat the complicated pathophysiology of chronic wounds. Challenges that will need to be addressed include development of a robust chronic wound model and MNAs that combine complex functionality with simplicity of use.