Current status and future outlook of nano-based systems for burn wound management

Zinc/aluminum-layered double hydroxide-gallic acid doped carboxymethyl cellulose nanocomposite films for wound healing

Effective loading and delivering the wound healing-based materials to the wound site and area with an optimum concentration and limited cytotoxicity are essential for a complete and fast healing process. Here, we have designed Zn/Al-LDH nanoparticles-loaded CMC films for encapsulation and delivery of gallic acid (GA) in order to develop an effective and efficient wound-healing scaffold. The physicochemical properties of the prepared Zn/Al-LDH nanohybrids were thoroughly characterized by several characterization techniques, such as FESEM, Hi-TEM, FTIR, and XRD techniques. The thermal properties of the scaffolds were evaluated by DSC and TGA analysis. The release profiles of GA from fabricated films were studied over 8 h by UV-vis spectroscopy. In vitro drug release studies in PBS solutions with pH 7.4 showed a mono-phasic profile in which the liberation of the drug mainly occurred by scaffold erosion and increased by increasing the experiment period. The in vitro antibacterial activity of Zn/Al-LDH-GA-loaded CMC films was assessed by disk diffusion and cell viability contact tests. The results showed the desired antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria. Incorporating GA within CMC and CMC-Zn/Al-LDH films rereleased good cytocompatibility at the studied incubation time and different concentrations toward human normal HFF cell line than the free drug. The results of the present study indicated that the Zn/Al-LDH and Zn/Al-LDH-GA-loaded CMC have promising wound healing features to further develop a better future for clinical remedy of the different non-healing and hard-to-heal wounds.

Biomimetic nanoparticles of platelet membranes carrying bFGF and VEGFA genes promote deep burn wound healing

INTRODUCTION

The treatment of burn wounds, especially deep burn wounds, remains a major clinical challenge. Growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor A (VEGFA) show great potential in promoting the healing of damaged tissues. This study explored wound healing following targeted delivery of bFGF and VEGFA genes into deep burn wounds through a novel platelet membrane-coated nanoparticle (PM@gene-NP) complex delivery system.

METHODS

First, bFGF and VEGFA genes were inserted into plasmid (pEGFP-N1) vectors. Subsequently, the assembled plasmids were loaded onto nanoparticles to form gene-loaded nanoparticle complexes, which were then wrapped with extracted platelet membrane, fully simulating the characteristics of platelets, in order to actively target sites of inflammatory damage. After administration of PM@gene-NP complexes through the tail vein of rats, a series of experiments were conducted to evaluate wound healing.

RESULTS

The PM@gene-NP complexes effectively targeted the burn sites. After the administration of the PM@gene-NP complexes, the rats exhibited increased blood flow in the burn wounds, which also healed faster than control groups. Histological results showed fewer inflammatory cells in the burned skin tissue after treatment. After the wounds healed, the production of hair follicles, sebaceous glands and other skin accessories in the skin tissue increased.

CONCLUSION

Our results showed that the PM@gene-NP complexes can effectively deliver gene therapy to the injured area, and this delivery system should be considered as a potential method for treating deep burns.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Research frontiers and hotspots in bacterial biofilm wound therapy: bibliometric and visual analysis for 2012-2022

Background

Bacterial biofilms, which can protect bacteria from host immune response and drug attack, are an important factor in the difficult healing of chronic wound infection, which has become a major problem in medical development. This paper aimed to analyze literature related to bacterial biofilm wound treatment published between 2012 and 2022 using bibliometric and visual analysis.

Methods

Publications related to bacterial biofilm wound treatment from 2012 to 2022 were selected from the Web of Science Core Collection. Microsoft Excel 2021, bibliometrics, CiteSpace6.1, and VOSviewer1.6.18 were used to extract and analyze data.

Results

A total of 940 articles were published between 2012 and 2022, with the United States being the leading country (with 302 papers, 32.13%) and the University of Copenhagen in Denmark being the leading institution (with 26 published articles) in the field. Steven L Percival, a British academic, published the most articles (14). In the field of bacterial biofilm wound treatment, keywords suggested that the research gradually transitioned from lower limb venous ulcer, negative pressure-assisted healing to chronic wound, in-vitro bacterial biological model research, and then to the development of more microscopic and more advanced technologies such as antibacterial activity and nanomaterials. "Nanoparticles", "inhibition/antibacterial", "delivery", "gold nanoparticles", "hydrogel", "wound healing", etc., may become new research hotspots in this field.

Conclusion

There is a lack of specific and effective treatment methods for diagnosing and treating bacterial biofilms in wounds. Through the development of multidisciplinary cooperation, early diagnosis and treatment of bacterial biofilms in wounds can be achieved. These data may provide a useful reference for scholars studying more effective bacterial biofilm wound treatment.

Investigating the active chemical constituents and pharmacology of Nanocnide lobata in the treatment of burn and scald injuries

OBJECTIVE

To identify the most effective fraction of Nanocnide lobata in the treatment of burn and scald injuries and determine its bioactive constituents.

METHODS

Chemical identification methods were used to analyze solutions extracted from Nanocnide lobata using petroleum ether, ethyl acetate, n-butanol using a variety of color reactions. The chemical constituents of the extracts were identified by ultra-performance liquid chromatography (UPLC)-mass spectrometry (MS). A total of 60 female mice were randomly divided into the following 6 groups: the petroleum ether extract-treated group; the ethyl acetate extract-treated group; the n-butanol extract-treated group; the model group; the control group; and the positive drug group. The burn/scald model was established using Stevenson's method. At 24 hours after modeling, 0.1 g of the corresponding ointment was evenly applied to the wound in each group. Mice in the model group did not undergo treatment, while those in the control group received 0.1 g of Vaseline. Wound characteristics, including color, secretions, hardness, and swelling, were observed and recorded. Photos were taken and the wound area calculated on the 1st, 5th, 8th, 12th, 15th, 18th and 21st days. Hematoxylin-eosin (HE) staining was utilized to observe the wound tissue of mice on the 7th, 14th, and 21st days. An enzyme-linked immunosorbent assay (ELISA) kit was used to measure the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-10, vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β1.

RESULTS

The chemical constituents of Nanocnide lobata mainly include volatile oils, coumarins, and lactones. UPLC-MS analysis revealed 39 main compounds in the Nanocnide lobata extract. Among them, ferulic acid, kaempferitrin, caffeic acid, and salicylic acid have been confirmed to exhibit anti-inflammatory and antioxidant activity related to the treatment of burns and scalds. HE staining revealed a gradual decrease in the number of inflammatory cells and healing of the wounds with increasing time after Nanocnide lobata extract administration. Compared with the model group, the petroleum ether extract-treated group showed significant differences in the levels of TNF-α (161.67±4.93, 106.33±3.21, 77.67±4.04 pg/mL) and IL-10 (291.77±4.93, 185.09±9.54, 141.33±1.53 pg/mL) on the 7th, 14th, and 21st days; a significant difference in the content of TGF-β1 (75.68±3.06 pg/mL) on the 21st day; and a significant difference in the level of VEGF (266.67±4.73, 311.33±10.50 pg/mL) on the 7th and 14th days respectively.

CONCLUSION

Petroleum ether Nanocnide lobata extract and the volatile oil compounds of Nanocnide lobata might be effective drugs in the treatment of burn and scald injuries, as they exhibited a protective effect on burns and scalds by reducing the expression of TNF-α, IL-10 and TGF-β1 and increasing the expression of VEGF. In addition, these compounds may also exert pharmacological effects that promote wound tissue repair, accelerate wound healing, and reduce scar tissue proliferation, inflammation and pain.

Exploring the potential of antimalarial nanocarriers as a novel therapeutic approach

Malaria is a life-threatening parasitic disease that affects millions of people worldwide, especially in developing countries. Despite advances in conventional therapies, drug resistance in malaria parasites has become a significant concern. Hence, there is a need for a new therapeutic approach. To combat the disease effectively means eliminating vectors and discovering potent treatments. The nanotechnology research efforts in nanomedicine show promise by exploring the potential use of nanomaterials that can surmount these limitations occurring with antimalarial drugs, which include multidrug resistance or lack of specificity when targeting parasites directly. Utilizing nanomaterials would possess unique advantages over conventional chemotherapy systems by increasing the efficacy levels while reducing side effects significantly by delivering medications precisely within the diseased area. It also provides cheap yet safe measures against Malaria infections worldwide-ultimately improving treatment efficiency holistically without reinventing new methods therapeutically. This review is an effort to provide an overview of the various stages of malaria parasites, pathogenesis, and conventional therapies, as well as the treatment gap existing with available formulations. It explores different types of nanocarriers, such as liposomes, ethosomal cataplasm, solid lipid nanoparticles, nanostructured lipid carriers, polymeric nanocarriers, and metallic nanoparticles, which are frequently employed to boost the efficiency of antimalarial drugs to overcome the challenges and develop effective and safe therapies. The study also highlights the improved pharmacokinetics, enhanced drug bioavailability, and reduced toxicity associated with nanocarriers, making them a promising therapeutic approach for treating malaria.

Potential of nanoformulations in malaria treatment

Malaria is caused by the protozoan Plasmodium sp and affects millions of people worldwide. Its clinical form ranges from asymptomatic to potentially fatal and severe. Current treatments include single drugs such as chloroquine, lumefantrine, primaquine, or in combination with artemisinin or its derivatives. Resistance to antimalarial drugs has increased; therefore, there is an urgent need to diversify therapeutic approaches. The disease cycle is influenced by biological, social, and anthropological factors. This longevity and complexity contributes to the records of drug resistance, where further studies and proposals for new therapeutic formulations are needed for successful treatment of malaria. Nanotechnology is promising for drug development. Preclinical formulations with antimalarial agents have shown positive results, but only a few have progressed to clinical phase. Therefore, studies focusing on the development and evaluation of antimalarial formulations should be encouraged because of their enormous therapeutic potential.

Nano-Enabled Chronic Wound Healing Strategies: Burn and Diabetic Ulcer Wounds

The human skin serves as the body’s first line of defense against the environment. Diabetes mellitus (DM) and 2nd–4th degree burns, on the other hand, affect the skin’s protective barrier features. Burn wounds, hypermetabolic state, and hyperglycemia compromise the immune system leading to chronic wound healing. Unlike acute wound healing processes, chronic wounds are affected by reinfections which can lead to limb amputation or death. The conventional wound dressing techniques used to protect the wound and provide an optimal environment for repair have their limitations. Various nanomaterials have been produced that exhibit distinct features to tackle issues affecting wound repair mechanisms. This review discusses the emerging technologies that have been designed to improve wound care upon skin injury. To ensure rapid healing and possibly prevent scarring, different nanomaterials can be applied at different stages of healing (hemostasis, inflammation, proliferation, remodeling).

Innovative Treatment Strategies to Accelerate Wound Healing: Trajectory and Recent Advancements

Wound healing is highly specialized dynamic multiple phase process for the repair of damaged/injured tissues through an intricate mechanism. Any failure in the normal wound healing process results in abnormal scar formation, and chronic state which is more susceptible to infections. Chronic wounds affect patients’ quality of life along with increased morbidity and mortality and are huge financial burden to healthcare systems worldwide, and thus requires specialized biomedical intensive treatment for its management. The clinical assessment and management of chronic wounds remains challenging despite the development of various therapeutic regimens owing to its painstakingly long-term treatment requirement and complex wound healing mechanism. Various conventional approaches such as cell therapy, gene therapy, growth factor delivery, wound dressings, and skin grafts etc., are being utilized for promoting wound healing in different types of wounds. However, all these abovementioned therapies are not satisfactory for all wound types, therefore, there is an urgent demand for the development of competitive therapies. Therefore, there is a pertinent requirement to develop newer and innovative treatment modalities for multipart therapeutic regimens for chronic wounds. Recent developments in advanced wound care technology includes nanotherapeutics, stem cells therapy, bioengineered skin grafts, and 3D bioprinting-based strategies for improving therapeutic outcomes with a focus on skin regeneration with minimal side effects. The main objective of this review is to provide an updated overview of progress in therapeutic options in chronic wounds healing and management over the years using next generation innovative approaches. Herein, we have discussed the skin function and anatomy, wounds and wound healing processes, followed by conventional treatment modalities for wound healing and skin regeneration. Furthermore, various emerging and innovative strategies for promoting quality wound healing such as nanotherapeutics, stem cells therapy, 3D bioprinted skin, extracellular matrix-based approaches, platelet-rich plasma-based approaches, and cold plasma treatment therapy have been discussed with their benefits and shortcomings. Finally, challenges of these innovative strategies are reviewed with a note on future prospects.

Nanobiotechnology: Applications in Chronic Wound Healing

Wounds occur when skin integrity is broken and the skin is damaged. With progressive changes in the disease spectrum, the acute wounds caused by mechanical trauma have been become less common, while chronic wounds triggered with aging, diabetes and infection have become more frequent. Chronic wounds now affect more than 6 million people in the United States, amounting to 10 billion dollars in annual expenditure. However, the treatment of chronic wounds is associated with numerous challenges. Traditional remedies for chronic wounds include skin grafting, flap transplantation, negative-pressure wound therapy, and gauze dressing, all of which can cause tissue damage or activity limitations. Nanobiotechnology — which comprises a diverse array of technologies derived from engineering, chemistry, and biology — is now being applied in biomedical practice. Here, we review the design, application, and clinical trials for nanotechnology-based therapies for chronic wound healing, highlighting the clinical potential of nanobiotechnology in such treatments. By summarizing previous nanobiotechnology studies, we lay the foundation for future wound care via a nanotech-based multifunctional smart system.

Nanoengineered therapeutic scaffolds for burn wound management

BACKGROUND

Wound healing is a complex process, and selecting an appropriate treatment is crucial and varies from one wound to another. Among injuries, burn wounds are more challenging to treat. Different dressings and scaffolds come into play when skin is injured. These scaffolds provide the optimum environment for wound healing. With the advancements of nanoengineering, scaffolds have been engineered to improve wound healing with lower fatality rates.

OBJECTIVES

Nanoengineered systems have emerged as one of the promising candidates for burn wound management. This review paper aims to provide an in-depth understanding of burn wounds and the role of nanoengineering in burn wound management. The advantages of nanoengineered scaffolds, their properties, and their proven effectiveness have been discussed. Nanoparticles and nanofibers-based nanoengineered therapeutic scaffolds provide optimum protection, infection management, and accelerated wound healing due to their unique characteristics. These scaffolds increase cell attachment and proliferation for desired results.

RESULTS

The literature review suggested that the utilization of nanoengineered scaffolds has accelerated burn wound healing. Nanofibers provide better cell attachment and proliferation among different nanoengineered scaffolds due to their 3D structure mimics the body's extracellular matrix.

CONCLUSION

With the application of these advanced nanoengineered scaffolds, better burn wound management is possible due to sustained drug delivery, better cell attachment, and an infection-free environment.

Review of History of Basic Principles of Burn Wound Management

Thermal energy is an essential and useful resource to humans in modern society. However, a consequence of using heat carelessly is burns. Burn injuries have various causes, such as exposure to flame, radiation, electrical, and chemical sources. In this study, we reviewed the history of burn wound care while focusing on the basic principles of burn management. Through this review, we highlight the need for careful monitoring and customization when treating burn victims at each step of wound care, as their individual needs may differ. We also propose that future research should focus on nanotechnology-based skin grafts, as this is a promising area for further improvement in wound care.

Engineering PD-L1 Cellular Nanovesicles Encapsulating Epidermal Growth Factor for Deep Second-Degree Scald Treatment

Scars are common and intractable consequences after scalded wound healing, while monotherapy of epidermal growth factors does not solve this problem. Maintaining the stability of epidermal growth factors and promoting scarless healing of wounds is paramount. In this study, engineering cellular nanovesicles overexpressing PD-L1 proteins, biomimetic nanocarriers with immunosuppressive efficacy, were successfully prepared to encapsulate epidermal growth factors for maintaining its bioactivity. Remarkably, PD-L1 cellular nanovesicles encapsulating epidermal growth factors (EGF@PDL1 NVs) exerted desired therapeutic effect by attenuating the overactivation of T cell immune response and promoting skin cells migration and proliferation. Hence, EGF@PD-L1 NVs promoted wound healing and prevented scarring in deep second-degree scald treatment, demonstrating a better effect than using individual PD-L1 NVs or EGF. This research proved that EGF@PD-L1 NVs is considered an innovative and thorough therapy of deep second-degree scald.

Nanomaterial-Based Therapy for Wound Healing

Poor wound healing affects millions of people globally, resulting in increased mortality rates and associated expenses. The three major complications associated with wounds are: (i) the lack of an appropriate environment to enable the cell migration, proliferation, and angiogenesis; (ii) the microbial infection; (iii) unstable and protracted inflammation. Unfortunately, existing therapeutic methods have not solved these primary problems completely, and, thus, they have an inadequate medical accomplishment. Over the years, the integration of the remarkable properties of nanomaterials into wound healing has produced significant results. Nanomaterials can stimulate numerous cellular and molecular processes that aid in the wound microenvironment via antimicrobial, anti-inflammatory, and angiogenic effects, possibly changing the milieu from nonhealing to healing. The present article highlights the mechanism and pathophysiology of wound healing. Further, it discusses the current findings concerning the prospects and challenges of nanomaterial usage in the management of chronic wounds.

Self-assembled magnetic polymeric micelles for delivery of quercetin: Toxicity evaluation on isolated rat liver mitochondria

Multifunctional nanocarriers as a promising platform could provide numerous opportunities in the field of drug delivery. Drug carriers loaded with both magnetic nanoparticles (MNPs) and therapeutic agents would allow the combination of chemotherapy with the possibility of monitoring or controlling the distribution of the nano vehicles in the body which may improve the effectiveness of the therapy. Furthermore, by applying these strategies, triggering drug release and/or synergistic hyperthermia treatment are also reachable. This study aimed to explore the potential of the quercetin (QUR) loaded magnetic nano-micelles for improving drug bioavailability while reducing the drug adverse effects. The bio-safety of developed QUR loaded magnetic nano-micelles (QMNMs) were conducted via mitochondrial toxicity using isolated rat liver mitochondria including glutathione (GSH), malondialdehyde (MDA), and the ferric reducing ability of plasma (FRAP). QMNMs with a mean particle size of 85 nm (PDI value of 0.269) and great physical stability were produced. Also, TEM images indicated that the prepared QMNMs were semi-spherical in shape. These findings also showed that the constructed QMNMs, as a pH-sensitive drug delivery system, exhibited a stable and high rate of QUR release under mildly acidic conditions pH (5.3) compared to neutral pH (7.4). The most striking result to emerge from the data is that an investigation of various mitochondrial functional parameters revealed that both QMNMs and QUR have no specific mitochondrial toxicity. Altogether, these results offer overwhelming evidence for the bio-safety of QMNMs and might be used as an effective drug delivery system for targeting and stimuli-responsive QUR delivery.

Recent advances in nanotherapeutics for the treatment of burn wounds

Moderate or severe burns are potentially devastating injuries that can even cause death, and many of them occur every year. Infection prevention, anti-inflammation, pain management and administration of growth factors play key roles in the treatment of burn wounds. Novel therapeutic strategies under development, such as nanotherapeutics, are promising prospects for burn wound treatment. Nanotherapeutics, including metallic and polymeric nanoformulations, have been extensively developed to manage various types of burns. Both human and animal studies have demonstrated that nanotherapeutics are biocompatible and effective in this application. Herein, we provide comprehensive knowledge of and an update on the progress of various nanoformulations for the treatment of burn wounds.

Nanomaterials applied in wound healing: Mechanisms, limitations and perspectives

Internal and external factors cause various types of wounds on the skin. Infections, nonhealing chronic wounds, and aesthetic and functional recovery all cause challenges for clinicians. The development of nanotechnology in biomedicine has brought many new materials, methods and therapeutic targets for the treatment of wounds, which are believed to have great prospects. In this work, the nanomaterials applied in different stages to promote wound healing and systematically expounded their mechanisms were reviewed. Then, the difficulties and defects of the present research and suggested methods for improvement were pointed out. Moreover, based on the current application status of nanomaterials in wound treatment, some new ideas for subsequent studies were proposed and the feasibility of intelligent healing by real-time monitoring, precision regulation, and signal transmission between electronic signals and human nerve signals in the future were discussed. This review will provide valuable directions and spark new thoughts for researchers.

Recent advances in targeting malaria with nanotechnology-based drug carriers

Malaria, as one of the most common human infectious diseases, remains the greatest global health concern, since approximately 3.5 billion people around the world, especially those in subtropical areas, are at the risk of being infected by malaria. Due to the emergence and spread of drug resistance to the current antimalarials, malaria-related mortality and incidence rates have recently increased. To overcome the aforementioned obstacles, nano-vehicles based on biodegradable, natural, and non-toxic polymers have been developed. Accordingly, these systems are considered as a potential drug vehicle, which due to their unique properties such as the excellent safety profile, good biocompatibility, tunable structure, diversity, and the presence of functional groups within the polymer structure, could facilitate covalent attachment of targeting moieties and antimalarials to the polymeric nano-vehicles. In this review, we highlighted some recent developments of liposomes as unique nanoscale drug delivery vehicles and several polymeric nanovehicles, including hydrogels, dendrimers, self-assembled micelles, and polymer-drug conjugates for the effective delivery of antimalarials.

An Insight into Biomolecules for the Treatment of Skin Infectious Diseases

In assigning priorities, skin infectious diseases are frequently classified as minor when compared to infectious diseases of high mortality rates, such as tuberculosis or HIV. However, skin infections are amongst the most common and prevalent diseases worldwide. Elderly individuals present an increased susceptibility to skin infections, which may develop atypical signs and symptoms or even complicate pre-existing chronic disorders. When the skin fails to correct or inhibit the action of certain pathogenic microorganisms, biomolecules endowed with antimicrobial features are frequently administered topically or systemically to assist or treat such conditions. (1) Antibiotics, (2) antimicrobial peptides, or (3) natural extracts display important features that can actively inhibit the propagation of these pathogens and prevent the evolution of infectious diseases. This review highlights the properties and mechanisms of action of these biomolecules, emphasizing their effects on the most prevalent and difficult to treat skin infections caused by pathogenic bacteria, fungi, and viruses. The versatility of biomolecules’ actions, their symbiotic effects with skin cells and other inherent antimicrobial components, and their target-directed signatures are also explored here.

Recent trends on burn wound care: hydrogel dressings and scaffolds

Acute and chronic wounds can cause severe physical trauma to patients and also result in an immense socio-economic burden. Thus, wound management has attracted increasing attention in recent years. However, burn wound management is still a major challenge in wound management. Autografts are often considered the gold-standard for burn care, but their application is limited by many factors. Hence, ideal burn dressings and skin substitute dressings are desirable. With the development of biomaterials and progress of tissue engineering technology, some innovative dressings and tissue engineering scaffolds, such as nanofibers, films, foams and hydrogels, have been widely used in the field of biomedicine, especially in wound management. Among them, hydrogels have attracted tremendous attention with their unique advantages. In this review, we discuss the challenges in burn wound management, several crucial design considerations with respect to hydrogels for burn wound healing, and available polymers for hydrogels in burn wound care. In addition, the potential application and plausible prospect of hydrogels are also highlighted.

Nanotechnology against the novel coronavirus (severe acute respiratory syndrome coronavirus 2): diagnosis, treatment, therapy and future perspectives

COVID-19, as an emerging infectious disease, has caused significant mortality and morbidity along with socioeconomic impact. No effective treatment or vaccine has been approved yet for this pandemic disease. Cutting-edge tools, especially nanotechnology, should be strongly considered to tackle this virus. This review aims to propose several strategies to design and fabricate effective diagnostic and therapeutic agents against COVID-19 by the aid of nanotechnology. Polymeric, inorganic self-assembling materials and peptide-based nanoparticles are promising tools for battling COVID-19 as well as its rapid diagnosis. This review summarizes all of the exciting advances nanomaterials are making toward COVID-19 prevention, diagnosis and therapy.

Nanocomposite scaffolds for accelerating chronic wound healing by enhancing angiogenesis

Skin is the body's first barrier against external pathogens that maintains the homeostasis of the body. Any serious damage to the skin could have an impact on human health and quality of life. Tissue engineering aims to improve the quality of damaged tissue regeneration. One of the most effective treatments for skin tissue regeneration is to improve angiogenesis during the healing period. Over the last decade, there has been an impressive growth of new potential applications for nanobiomaterials in tissue engineering. Various approaches have been developed to improve the rate and quality of the healing process using angiogenic nanomaterials. In this review, we focused on molecular mechanisms and key factors in angiogenesis, the role of nanobiomaterials in angiogenesis, and scaffold-based tissue engineering approaches for accelerated wound healing based on improved angiogenesis.

pH-sensitive curcumin conjugated micelles for tumor triggered drug delivery

Development of new drugs are confronted with some barriers and challenges, since these projects are mainly expensive, complex, time consuming with lack of success, there is an urgent need to reformulate the current poorly water soluble anti-cancer drugs. In this study, a new type of polymer-curcumin conjugates based on glycidyl azide polymer (GAP) was developed for cancer therapy. The copolymer was used for delivery of curcumin (CUR) as an anticancer drug to cancer cells. Our method is based on the facile conjugation of CUR to amine-containing polymeric vehicles through imine linkage bonds, which could remain stable in normal physiological condition while readily dissociate by an acidic environment and make the prodrug active to liberate its payload CUR to inhibit cell growth. The results demonstrated that fabricated amphiphilic PDCs were self-assembled into nanosized micelles in aqueous solution and the micelles showed an average size of 180 nm with a good polydispersity index. Drug release studies demonstrated that this nano-conjugate is fairly stable at physiologic environments but prone to mild acidic conditions which would trigger the release of conjugated CUR. Moreover, the PDCs micelles exhibited excellent cytotoxicity effect on 4T1 mouse breast cancer cell line but no significant toxicity was observed for the copolymer. In addition, the copolymer did not display remarkable toxicity against A. salina even at high doses of copolymer. In addition, the synthesized PDCs exhibited hemolysis lowers than 6%. The safety of copolymers as a drug vehicle was also confirmed by LD₅₀, since all mice which treated with 5000 mg/Kg (limited dose) were still alive after one week. Our findings revealed that these unique pH-sensitive PDCs may provide a promising approach for delivery of the anticancer drugs to cancer cells.[Formula: see text].

Photodynamic Activity of Tribenzoporphyrazines with Bulky Periphery against Wound Bacteria

Magnesium(II) tribenzoporphyrazines with phenoxybutylsulfanyl substituents were evaluated as photosensitizers in terms of their optical properties against wound bacteria. In the UV-vis spectra of analyzed tribenzoporphyrazines, typical absorption ranges were found. However, the emission properties were very weak, with fluorescence quantum yields in the range of only 0.002–0.051. What is important, they revealed moderate abilities to form singlet oxygen with the quantum yields up to 0.27. Under irradiation, the macrocycles decomposed via photobleaching mechanism with the quantum yields up to 8.64 × 10⁻⁵. The photokilling potential of tribenzoporphyrazines was assessed against Streptococcus pyogenes, Staphylococcus epidermidis, as well as various strains of Staphylococcus aureus, including methicillin-sensitive and-resistant bacteria. Both evaluated photosensitizers revealed high photodynamic potential against studied bacteria (>3 logs). S.aureus growth was reduced by over 5.9 log, methicillin-resistant S. aureus by 5.1 log, S.epidermidis by over 5.7 log, and S. pyogenes by over 4.7 log.