Carboxymethyl chitosan modified lipid nanoformulations as a highly efficacious and biocompatible oral anti-leishmanial drug carrier system

Repair effects of thermosensitive hydrogels combined with iPSC-derived corneal endothelial cells on rabbit corneal endothelial dysfunction

Considering the limitations of human corneal endothelial cell proliferation as well as the severe shortage of corneal donations, it is imperative to develop improved methods of corneal endothelial cell transplantation. The purpose of this study was to construct a modified corneal endothelial cell transplantation approach using thermosensitive hydrogels combined with induced pluripotent stem cells (iPSCs)-derived human corneal endothelial cells (hCECs). In this study, thermosensitive hydrogels hydroxypropyl chitin/carboxymethyl chitosan (HPCH/CMCS) were fabricated, and their hydrogels properties and biocompatibility were investigated. Our results demonstrated that HPCH/CMCS hydrogels exhibited superior transparency, appropriate mechanical properties and favorable biocompatibility. A two-step induction method of small molecule compounds was employed, by which iPSCs were differentiated into hCECs via neural crest cells (NCCs). Additionally, a rabbit corneal endothelial dysfunction model was established in vivo, aiming to evaluate the safety and effectiveness of the combined method. Slit lamp microscope results indicated that significant transparency improvement could be noted in HPCH/CMCS/hCECs group (P = 0.006), whereas the corneal transparency was not homogeneous in different areas. Moreover, histological examinations and immunofluorescence analysis revealed that HPCH/CMCS/hCECs group showed a higher density of corneal endothelial cells and positive expressions of related markers. This study may provide ideas and experimental basis for the combined application of hydrogels and iPSC-derived corneal endothelial cells for corneal endothelial dysfunction. STATEMENT OF SIGNIFICANCE: Corneal transplantation is the most effective treatment for corneal endothelial dysfunction, which is challenged by issues such as corneal donor shortages and immune rejection. In this study, we proposed a combined transplantation method of cells and hydrogels for corneal endothelial dysfunction. We modified the protocols to obtain corneal endothelial cells from iPSCs by a two-step induction method. Besides, thermosensitive hydrogels with satisfactory biocompatibility and degradability were fabricated as fixation and support carriers of iPSC-derived corneal endothelial cells for in vivo transplantation. Experimental results demonstrated that this method could locally repair corneal endothelial dysfunction in rabbits, with the repaired corneas expressing relevant markers. This study presented a preliminary attempt to combine hydrogels and cells for corneal endothelial dysfunction.

Biomaterials with antifungal strategies to fight oral infections

Oral fungal infections pose a threat to human health and increase the economic burden of oral diseases by prolonging and complicating treatment. A cost-effective strategy is to try to prevent these infections from happening in the first place. With this purpose, biomaterials with antifungal properties are a crucial element to overcome fungal infections in the oral cavity. In this review, we go through different kinds of biomaterials and coatings that can be used to functionalize them. We also review their potential as a therapeutic approach in addition to prophylaxis, by going through traditional and alternative antifungal compounds, e.g., essential oils, that could be incorporated in them, to enhance their efficacy against fungal pathogens. We aim to highlight the potential of these technologies and propose questions that need to be addressed in prospective research. Finally, we intend to concatenate the key aspects and technologies on the use of biomaterials in oral health, to create an easy to find summary of the current state-of-the-art for researchers in the field.

Revolutionizing Leishmaniasis Treatment with Cutting Edge Drug Delivery Systems and Nanovaccines: An Updated Review

Leishmaniasis, one of the most overlooked tropical diseases, is a life-threatening illness caused by the parasite Leishmania donovani that is prevalent in underdeveloped nations. Over 350 million individuals in more than 90 different nations worldwide are at risk of contracting the disease, which has a current fatality rate of 50 000 mortalities each year. The administration of liposomal Amp B, pentavalent antimonials, and miltefosine are still considered integral components of the chemotherapy regimen. Antileishmanial medications fail to treat leishmaniasis because of their numerous drawbacks. These include inadequate effectiveness, toxicity, undesired side effects, drug resistance, treatment duration, and cost. Consequently, there is a need to overcome the limitations of conventional therapeutics. Nanotechnology has demonstrated promising outcomes in addressing these issues because of its small size and distinctive characteristics, such as enhanced bioavailability, lower toxicity, biodegradability, and targeted drug delivery. This review is an effort to highlight the recent progress in various nanodrug delivery systems (nDDSs) over the past five years for treating leishmaniasis. Although the preclinical outcomes of nDDSs have shown promising treatment for leishmaniasis, further research is needed for their clinical translation. Advancement in three primary priority domains─molecular diagnostics, clinical investigation, and knowledge dissemination and standardization─is imperative to propel the leishmaniasis field toward translational outcomes.

Developing nanosize carrier systems for Amphotericin-B: A review on the biomedical application of nanoparticles for the treatment of leishmaniasis and fungal infections

New formulations of Amphotericin-B (Am-B), the most popular therapeutic drug for many human infections such as parasitic and fungal pathogens, are safe, economical, and effective in the world. Several newly designed carrier systems for Am-B can also be considered orally with sufficient gastrointestinal permeability and good solubility. However, the clinical application of several new formulations of Am-B with organ cytotoxicity, low bioavailability, high costs, and technical problems have caused some issues. Therefore, more attention and scientific design are required to progress safe and effective drug delivery systems. Currently, the application of nano-based technology and nanomaterials in the advancement of drug delivery systems exhibits promising outcomes to cure many human systemic infections. Designing novel drug delivery systems including solid lipid nanostructured materials, lipo-polymersomes, drug conjugates and microneedles, liposomes, polymer and protein-based nanostructured materials, dendrimers, emulsions, mixed micelles, polymeric micelles, cyclodextrins, nanocapsules, and nanocochleate for Am-B has many advantages to reducing several related issues. The unique properties of nanostructured particles such as proper morphology, small size, surface coatings, and, electrical charge, permit scientists to design new nanocomposite materials against microorganisms for application in various human diseases. These features have made these nanoparticles an ideal candidate for drug delivery systems in clinical approaches to cure a number of human disorders and currently, several therapeutic nanostructured material formulations are under different stages of clinical tests. Hence, this scientific paper mainly discussed the advances in new formulations of Am-B for the treatment of human systemic infections and related clinical tests.

An update on lipid-based nanodrug delivery systems for leishmaniasis treatment

Lipid-based nanodrug delivery systems hold considerable promise in therapeutic intervention for leishmaniasis by enhancing drug solubility and targeted delivery.

Development and Pharmacokinetic Evaluation of Novasomes for the Trans-nasal Delivery of Fluvoxamine Using Arachidonic Acid-Carboxymethyl Chitosan Conjugate

Depression is the major mental illness which causes along with loss of interest in daily life, a feeling of hopelessness, appetite or weight changes, anger and irritability. Due to the hepatic first-pass metabolism, the absolute bioavailability of fluvoxamine (FVM) after oral administration is about 50%. By avoiding the pre-systemic metabolism, nasal delivery would boost bioavailability of FVM. Additionally, the absorption is anticipated to occur more quickly than it would via the oral route because of the existence of microvilli and high vasculature. A nonionic surfactant, cholesterol and an arachidonic acid-carboxymethyl chitosan (AA-CMCS) conjugate were used to develop FVM-loaded novasomes. To investigate the effects of surfactant concentration, AA-CMCS conjugate concentration and stirring speed on the novasomes' characteristics, a Box-Behnken design was used. The dependent variables chosen were zeta potential, polydispersity index and particle size. The AA-CMCS conjugate was confirmed by 1H-NMR and FTIR. Using Design Expert software (version 7; Stat-Ease Inc., Minneapolis, MN, USA), novasomes were further optimized. The chosen optimal formulation (NAC8) was made up of AA-CMCS conjugate, Span 60 and cholesterol. Particle size, zeta potential and PDI values for NAC8 formulation were 101 nm, -35 mV and 0.263, respectively. The NAC8 formulation's DSC and TGA analysis demonstrated that the medication had been uniformly and amorphously distributed throughout the novasomes. The NAC8 formulation showed 99% and 90% FVM release and permeation, respectively, and the novasome adherence time was 24 h. An improved antidepressant effect along with five-fold increase in bioavailability of FVM was observed after trans-nasal administration of NAC8 formulation compared to the reference commercially available Flumin® tablets. FVM-loaded novasomes administered via the nasal route may therefore constitute an advancement in the management of depression.

Immunotherapy and immunochemotherapy in combating visceral leishmaniasis

Visceral leishmaniasis (VL), a vector-borne disease, is caused by an obligate intramacrophage, kinetoplastid protozoan parasite of the genus Leishmania. Globally, VL is construed of diversity and complexity concerned with high fatality in tropics, subtropics, and Mediterranean regions with ~50,000-90,000 new cases annually. Factors such as the unavailability of licensed vaccine(s), insubstantial measures to control vectors, and unrestrained surge of drug-resistant parasites and HIV-VL co-infections lead to difficulty in VL treatment and control. Furthermore, VL treatment, which encompasses several problems including limited efficacy, emanation of drug-resistant parasites, exorbitant therapy, and exigency of hospitalization until the completion of treatment, further exacerbates disease severity. Therefore, there is an urgent need for the development of safe and efficacious therapies to control and eliminate this devastating disease. In such a scenario, biotherapy/immunotherapy against VL can become an alternative strategy with limited side effects and no or nominal chance of drug resistance. An extensive understanding of pathogenesis and immunological events that ensue during VL infection is vital for the development of immunotherapeutic strategies against VL. Immunotherapy alone or in combination with standard anti-leishmanial chemotherapeutic agents (immunochemotherapy) has shown better therapeutic outcomes in preclinical studies. This review extensively addresses VL treatment with an emphasis on immunotherapy or immunochemotherapeutic strategies to improve therapeutic outcomes as an alternative to conventional chemotherapy.

Multi-functional carboxymethyl chitosan/sericin protein/halloysite composite sponge with efficient antibacterial and hemostatic properties for accelerating wound healing

The development of wound dressings with hemostatic and antibacterial properties has attracted great attention. In this study, we prepared a multi-functional natural substance sponge (CMC/Ser-Ag/HNT) composed of carboxymethyl chitosan (CMC), sericin-silver nanoparticle (Ser-Ag), and halloysite (HNT). CMC/Ser-Ag/HNT sponge was demonstrated to bear desired hygroscopicity, porosity, compressive strength and compressive stability, cytocompatibility, and hemocompatibility. The mechanical properties (compressive strength of 100 kPa) and hemostatic capacity (hemostasis time of 15 ± 3 s in the liver injury model and 12 ± 3 s in the caudal injury model) were enhanced by introducing HNT into the CMC sponge. Ser-Ag was synthesized in situ via the redox nature of tyrosine residues in sericin in a "one-step, green" way to enhance the antibacterial activity of the hybrid sponge against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In addition, the rat full-thickness skin defect model experiments demonstrated that the CMC/Ser-Ag/HNT4 sponge significantly promoted epithelialization and collagen formation. Immunofluorescence staining assays revealed that the composite sponge reduced inflammation by downregulating the expression of IL-6 and enhanced angiogenesis by upregulating VEGF expression. All the findings demonstrated the great potential of CMC/Ser-Ag/HNT sponge as versatile clinical wound dressing, especially for hemorrhagic and infected wounds.

Leishmaniasis and Chagas disease: Is there hope in nanotechnology to fight neglected tropical diseases?

Nanotechnology is revolutionizing many sectors of science, from food preservation to healthcare to energy applications. Since 1995, when the first nanomedicines started being commercialized, drug developers have relied on nanotechnology to improve the pharmacokinetic properties of bioactive molecules. The development of advanced nanomaterials has greatly enhanced drug discovery through improved pharmacotherapeutic effects and reduction of toxicity and side effects. Therefore, highly toxic treatments such as cancer chemotherapy, have benefited from nanotechnology. Considering the toxicity of the few therapeutic options to treat neglected tropical diseases, such as leishmaniasis and Chagas disease, nanotechnology has also been explored as a potential innovation to treat these diseases. However, despite the significant research progress over the years, the benefits of nanotechnology for both diseases are still limited to preliminary animal studies, raising the question about the clinical utility of nanomedicines in this field. From this perspective, this review aims to discuss recent nanotechnological developments, the advantages of nanoformulations over current leishmanicidal and trypanocidal drugs, limitations of nano-based drugs, and research gaps that still must be filled to make these novel drug delivery systems a reality for leishmaniasis and Chagas disease treatment.

From Static to Dynamic: A Review on the Role of Mucus Heterogeneity in Particle and Microbial Transport

Mucus layers (McLs) are on the front line of the human defense system that protect us from foreign abiotic/biotic particles (e.g., airborne virus SARS-CoV-2) and lubricates our organs. Recently, the impact of McLs on human health (e.g., nutrient absorption and drug delivery) and diseases (e.g., infections and cancers) has been studied extensively, yet their mechanisms are still not fully understood due to their high variety among organs and individuals. We characterize these variances as the heterogeneity of McLs, which lies in the thickness, composition, and physiology, making the systematic research on the roles of McLs in human health and diseases very challenging. To advance mucosal organoids and develop effective drug delivery systems, a comprehensive understanding of McLs' heterogeneity and how it impacts mucus physiology is urgently needed. When the role of airway mucus in the penetration and transmission of coronavirus (CoV) is considered, this understanding may also enable a better explanation and prediction of the CoV's behavior. Hence, in this Review, we summarize the variances of McLs among organs, health conditions, and experimental settings as well as recent advances in experimental measurements, data analysis, and model development for simulations.