High drug-loading gold nanoclusters for responsive glucose control in type 1 diabetes

From synthesis to applications of biomolecule-protected luminescent gold nanoclusters

Gold nanoclusters (AuNCs) are a class of novel luminescent nanomaterials that exhibit unique properties of ultra-small size, featuring strong anti-photo-bleaching ability, substantial Stokes shift, good biocompatibility, and low toxicity. Various biomolecules have been developed as templates or ligands to protect AuNCs with enhanced stability and luminescent properties for biomedical applications. In this review, the synthesis of AuNCs based on biomolecules including amino acids, peptides, proteins and DNA are summarized. Owing to the advantages of biomolecule-protected AuNCs, they have been employed extensively for diverse applications. The biological applications, particularly in bioimaging, biosensing, disease therapy and biocatalysis have been described in detail herein. Finally, current challenges and future potential prospects of bio-templated AuNCs in biological research are briefly discussed.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

Self-assembled chitosan-insulin oral nanoparticles - A critical perspective review

Chitosan is an abundant natural cationic polysaccharide with excellent biodegradability, bioadhesion, and biocompatibility. Chitosan is extensively researched for various particulate oral insulin drug delivery systems. Oral insulin is economically efficient and more convenient than injections, with greater patient compliance. Electrostatic ionic interaction between cationic chitosan and anionic polymer or insulin leads to the formation of spontaneously self-assembled nanoparticles. This simple technique attracted many researchers as it can be carried out quickly in mild conditions without harmful solvents, such as surfactants or chemical cross-linkers that might degrade the insulin structure. The formulated chitosan nanoparticles help to protect the core insulin from enzymatic degradation in the digestive system and improve paracellular intestinal uptake from the enterocytes due to mucoadhesion and reversible tight junction opening. Moreover, functionalized chitosan nanoparticles create newer avenues for targeted and prolonged delivery. This review focuses on modified chitosan-insulin nanoparticles and their implications on oral insulin delivery. Dependent variables and their optimal concentration ranges used in self-assembly techniques for chitosan-insulin nanoparticular synthesis are summarized. This review provides a comprehensive guide to fine-tune the essential factors to formulate stable insulin-chitosan nanoparticles using mild ionic interactions.

The insulin long-acting chitosan - Polyethyleneimine nanoparticles to treat the type 2 diabetes mellitus and prevent the associated complications

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder, which is ultimately treated by the insulin (INS). However, the subcutaneous (s. c.) injection of insulin solution faces the problems of pain and unsatisfactory patient compliance. In this study, the long-acting formulations of insulin are propsed to treat the T2DM and prevent the associated complications. The chitosan (CS) and/or branched polyethyleneimine (bPEI) nanoparticles (bPEI-INS NPs, CS-bPEI-INS NPs) were constructed to load insulin. The long -acting nanoparticles successfully achieved the sustained release of the INS in vitro and in vivo. After s. c. administration, the CS-bPEI-INS NPs greatly improved the INS bioavailability. As a result, the CS-bPEI-INS NPs produced sustained glucose-lowering effects, promising short-term and long-term hypoglycemic efficacy in the T2DM model. Furthermore, the treatment of the CS-bPEI-INS NPs greatly protected the islet in the pancreas and prevented the associated complications of the T2DM, such as cardiac fibrosis in the myocardial interstitium and the perivascular area. In a word, the CS-bPEI-INS NPs was an encouraging long-acting formulation of insulin and had great potential in the treatment of T2DM.

Nanobiotechnology-Modified Cellular and Molecular Therapy as a Novel Approach for Autoimmune Diabetes Management

Several cellular and molecular therapies such as stem cell therapy, cell replacement therapy, gene modification therapy, and tolerance induction therapy have been researched to procure a permanent cure for Type 1 Diabetes. However, due to the induction of undesirable side effects, their clinical utility is questionable. These anti-diabetic therapies can be modified with nanotechnological tools for reducing adverse effects by selectively targeting genes and/or receptors involved directly or indirectly in diabetes pathogenesis, such as the glucagon-like peptide 1 receptor, epidermal growth factor receptor, human leukocyte antigen (HLA) gene, miRNA gene and hepatocyte growth factor (HGF) gene. This paper will review the utilities of nanotechnology in stem cell therapy, cell replacement therapy, beta-cell proliferation strategies, immune tolerance induction strategies, and gene therapy for type 1 diabetes management.

Transdermal Insulin Delivery and Microneedles-based Minimally Invasive Delivery Systems

Diabetes has become a serious threat to human health, causing death and pain to numerous patients. Transdermal insulin delivery is a substitute for traditional insulin injection to avoid pain from the injection. Transdermal methods include non-invasive and invasive methods. As the non-invasive methods could hardly get through the stratum corneum, minimally invasive devices, especially microneedles, could enhance the transappendageal route in transcutaneous insulin delivery, and could act as connectors between the tissue and outer environment or devices. Microneedle patches have been in quick development in recent years and with different types, materials and functions. In those patches, the smart microneedle patch could perform as a sensor and reactor responding to glucose to regulate the blood level. In the smart microneedles field, the phenylboronic acid system and the glucose oxidase system have been successfully applied on the microneedle platform. Insulin transdermal delivery strategy, microneedles technology and smart microneedles' development would be discussed in this review.

Responsive hydrogel-based microneedle dressing for diabetic wound healing

Wound healing is a critical challenge in diabetic patients, mainly due to long-term dysglycemia and its related pathological complications. Subcutaneous insulin injection represents a typical clinical solution, while the low controllability of insulin administration commonly leads to a result far from the optimal therapeutic effect. In this work, we developed a glucose-responsive insulin-releasing hydrogel for microneedle dressing fabrication and then investigated its effects on diabetic wound healing. The hydrogel system was composed of biocompatible gelatin methacrylate (GelMa), glucose-responsive monomer 4-(2-acrylamidoethylcarbamoyl)-3-fluorophenylboronic acid (AFPBA) and gluconic insulin (G-insulin), and the Gel-AFPBA-ins hydrogel-based microneedle dressing was developed by replicating PDMS molds. The resultant hydrogel microneedle dressing exhibited adequate mechanical properties, high biocompatibility, glucose-responsive insulin release behavior upon exposure to different glucose solutions, and potent adhesion to the skin compared to hydrogels without microstructures. The microneedle dressing could accelerate the diabetic wound healing process with decreased inflammatory reaction, enhanced collagen deposition on the regenerated tissue sites, and improved blood glucose control in animals. Therefore, the glucose-responsive insulin-releasing hydrogel microneedle dressing is effective in diabetic wound management and has potential for treatment of other chronic skin injuries.

Therapeutic approaches targeting molecular signaling pathways common to diabetes, lung diseases and cancer

Diabetes mellitus (DM), is the most common metabolic disease and is characterized by sustained hyperglycemia. Accumulating evidences supports a strong association between DM and numerous lung diseases including chronic obstructive pulmonary disease (COPD), fibrosis, and lung cancer (LC). The global incidence of DM-associated lung disorders is rising and several ongoing studies, including clinical trials, aim to elucidate the molecular mechanisms linking DM with lung disorders, in particular LC. Several potential mechanisms, including hyperglycemia, hyperinsulinemia, glycation, inflammation, and hypoxia, are cited as plausible links between DM and LC. In addition, studies also propose a connection between the use of anti-diabetic medications and reduction in the incidence of LC. However, the exact cause for DM associated lung diseases especially LC is not clear and is an area under intense investigation. Herein, we review the biological links reported between DM and lung disorders with an emphasis on LC. Furthermore, we report common signaling pathways (eg: TGF-β, IL-6, HIF-1, PDGF) and miRNAs that are dysregulated in DM and LC and serve as molecular targets for therapy. Finally, we propose a nanomedicine based approach for delivering therapeutics (eg: IL-24 plasmid DNA, HuR siRNA) to disrupt signaling pathways common to DM and LC and thus potentially treat DM-associated LC. Finally, we conclude that the effective modulation of commonly regulated signaling pathways would help design novel therapeutic protocols for treating DM patients diagnosed with LC.

Identification of key genes in type 2 diabetes-induced erectile dysfunction rats with stem cell therapy through high-throughput sequencing and bioinformatic analysis

Diabetes mellitus erectile dysfunction (DMED) is a frequent complication of diabetes. Mesenchymal stem cell (MSC) therapy was demonstrated to improve erectile function in DMED. However, the pathogenesis of DMED and the mechanism by which MSCs function are still unclear. We established a rat model of DMED and gave MSC therapy through intracavernous injection. After transcriptome sequencing of rats' penile tissue, we identified a total of 1,097 overlapped differentially expressed genes (DEGs) of the normal control group, DMED group, and MSC-treated group, containing 189 upregulated genes and 908 downregulated genes. The enriched functions of upregulated DEGs included extracellular matrix organisation (GO:0030198), extracellular structure organisation (GO:0043062), and wound healing (GO:0042060), PPAR signalling pathway (rno03320), arachidonic acid metabolism (rno00590) and retinol metabolism (rno00830). The enriched functions of downregulated DEGs included peptidase activity (GO:0052547), hair follicle development (GO:0001942), intermediate filament-based process (GO:0045103), nitrogen metabolism (rno00910), aldosterone-regulated sodium reabsorption (rno04960) and retinol metabolism (rno00830). We constructed a PPI network with 547 nodes and 2,365 edges and identified 15 hub genes with high connectivity degree. In summary, 15 hub genes with potential roles in the development of ED were identified. Further functional research would be required to elucidate the molecular mechanism underlying misregulated genes.

A dissolving and glucose-responsive insulin-releasing microneedle patch for type 1 diabetes therapy

A dissolving microneedle patch for responsive insulin release and type 1 diabetes therapy.

A Glucose-Responsive Polymer Nanocarrier Based on Sulfonated Resorcinarene for Controlled Insulin Delivery

A nanocarrier (p(6SRA-5B)) for glucose-controlled insulin delivery consists of sulfonated resorcinarenes (SRA) that are assembled into a spherical shell and are attached to each other with phenylboronate linkers. p(6SRA-5B) is stable in water and blood plasma at normal glucose concentrations. At high glucose levels (>5 mM), p(6SRA-5B) dissociates into SRA and phenylboronates through competitive interaction with excess glucose. Insulin was successfully encapsulated into the cavity of p(6SRA-5B) and its release was investigated in water and blood plasma by NMR, UV, CD, and fluorescence spectroscopy. The results show that the dissociation of the nanocarrier and the insulin release occurs with an increase in glucose concentration. At 5 mM glucose, the nanocarrier is stable, and the insulin release does not exceed 10 %. Increasing the glucose concentration to 7.5-10 mM results in a 40-100 % insulin release. p(6SRA-5B) is thus a promising insulin nanocarrier for the treatment of type 1 diabetes.

Responsive principles and applications of smart materials in biosensing

Biosensing is a rising analytical field for detection of biological indicators using transducing systems. Smart materials can response to external stimuli, and translate the stimuli from biological domains into signals that are readable and quantifiable. Smart materials, such as nanomaterials, photonic crystals and hydrogels have been widely used for biosensing purpose. In this review, we illustrate the incorporation of smart materials in biosensing systems, including the design of responsive materials, their responsive mechanism of biosensing, and their applications in detection of four types of common biomolecules (including glucose, nucleic acids, proteins, and enzymes). In the end, we also illustrate the current challenges and prospective of using smart materials in biosensing research fields.