Glucose sensitive konjac glucomannan/concanavalin A nanoparticles as oral insulin delivery system

Multifunctional Microneedle Patches Loaded With Engineered Nitric Oxide-Releasing Nanocarriers for Targeted and Synergistic Chronic Wound Therapy

Chronic wounds impose significant physical and mental burdens on patients. Nano-based formulations offer a promising strategy for chronic wound healing due to their non-invasive nature and enhanced biofilms penetration, but they often lack targeting capability or fail to achieve long-term and synergistic effects. In this work, a multifunctional microneedle (MN) patch loaded with engineered nitric oxide (NO)-releasing nanocarriers are presented that encapsulate an antibacterial agent and are immobilized with Concanavalin A (Con A) and NO molecules for targeted and synergistic treatment of chronic wounds. With the assistance of MNs, the nanoparticles (NPs) can directly cross bacterial biofilms and be efficiently delivered to wound tissues, where they target harmful bacteria through the specific recognition between Con A and polysaccharides on bacterial surfaces, followed by the release of the encapsulated antimicrobial agent, thereby achieving effective antibacterial effect. Moreover, the NPs generate NO in a sustained manner as they dissociate in the wound tissue, which exerts potent anti-inflammatory action and benefits tissue regeneration, further promoting chronic wounds closure. Consequently, this work provides a novel MN patch loaded with engineered NPs designed for accelerating chronic wound healing through targeted and synergistic therapy.

Supramolecular approach to the design of nanocarriers for antidiabetic drugs: targeted patient-friendly therapy

Diabetes and its complications derived are among serious global health concerns that critically deteriorate the quality of life of patients and, in some cases, result in lethal outcome. Herein, general information on the pathogenesis, factors aggravating the course of the disease and drugs used for the treatment of two types of diabetes are briefly discussed. The aim of the review is to introduce supramolecular strategies that are currently being developed for the treatment of diabetes mellitus and that present a very effective alternative to chemical synthesis, allowing the fabrication of nanocontainers with switchable characteristics that meet the criteria of green chemistry. Particular attention is paid to organic (amphiphilic and polymeric) formulations, including those of natural origin, due to their biocompatibility, low toxicity, and bioavailability. The advantages and limitations of different nanosystems are discussed, with emphasis on their adaptivity to noninvasive administration routes.<br>The bibliography includes 378 references.

Recent Advances in the Drugs and Glucose-Responsive Drug Delivery Systems for the Treatment of Diabetes: A Systematic Review

Diabetes is a common chronic metabolic disease. Different types of drugs play important roles in controlling diabetes and its complications, but there are some limitations. The glucose-responsive drug delivery system is a novel technology with potential in diabetes treatment. It could automatically release drugs in response to changes in glucose levels in the body to maintain blood glucose within a normal range. The emergence of a glucose-sensitive drug delivery system provides a more intelligent and precise way to treat diabetes. The review is carried out according to the Preferred Reporting Items for Systematic Reviews (PRISMA 2020) guidelines This review focuses on the recent advances in the drugs and different systems of glucose-sensitive drug delivery, including glucose oxidase, phenylboronic acid, Concanavalin A, and other glucose-reactive systems. Furthermore, the glucose-responsive drug delivery system combined with the application applied in hydrogels, microneedles, and nanoparticles is also explored and summarized. The new platforms to sustain the release of anti-diabetic drugs could be desirable for patients. It could lead to increased adherence and glycemic outcomes for the detection and treatment of diabetes. Furthermore, given the limitations of glucose-responsive drug delivery systems, solutions and perspectives are proposed to help the understanding and application of these systems. This review will be helpful for drug discovery and treatment of diabetes from a new perspective.

Glucose-Responsive Microneedle Patch with High Insulin Loading Capacity for Prolonged Glycemic Control in Mice and Minipigs

Transdermal microneedle-mediated glucose-responsive insulin delivery systems can modulate insulin release based on fluctuations in blood glucose levels, thus maintaining normoglycemia effectively in a continuous, convenient, and minimally invasive manner. However, conventional microneedles are limited by the low drug loading capacity, making it challenging to be applied on human skin at a reasonable size for a lasting glucose-controlling effect, thus hindering their clinical translation. Here, we design a microneedle patch with a solid insulin powder core to achieve a high loading capacity of insulin (>70 wt %) as well as a glucose-sensitive polymeric shell to realize glucose-responsive insulin release. Once exposed to hyperglycemia, the formation of negatively charged glucose-boronate complexes increases the charge density of the shell matrix, leading to swelling of the shell and accelerating insulin release from the core. We have demonstrated that this glucose-responsive microneedle patch could achieve long-term regulation of blood glucose levels in both type 1 diabetic mice and minipigs (up to 48 h with patches of ∼3.5 cm2 for minipigs >25 kg).

3D-Printed Phenylboronic Acid-Bearing Hydrogels for Glucose-Triggered Drug Release

Diabetes is a major health concern that the next-generation of on-demand insulin releasing implants may overcome via personalized therapy. Therein, 3D-printed phenylboronic acid-containing implants with on-demand glucose-triggered drug release abilities are produced using high resolution stereolithography technology. To that end, the methacrylation of phenylboronic acid is targeted following a two-step reaction. The resulting photocurable phenylboronic acid derivative is accordingly incorporated within bioinert polyhydroxyethyl methacrylate-based hydrogels at varying loadings. The end result is a sub-centimeter scaled 3D-printed bioinert implant that can be remotely activated with 1,2-diols and 1,3-diols such as glucose for on-demand drug administration such as insulin. As a proof of concept, varying glucose concentration from hypoglycemic to hyperglycemic levels readily allow the release of pinacol, i.e., a 1,2-diol-containing model molecule, at respectively low and high rates. In addition, the results demonstrated that adjusting the geometry and size of the 3D-printed part is a simple and suitable method for tailoring the release behavior and dosage.

β-Cyclodextrin/dialdehyde glucan-coated keratin nanoparticles for oral delivery of insulin

Successful oral insulin administration can considerably enhance the quality of life (QOL) of diabetes patients who must frequently take insulin injections. However, Oral insulin administration is seriously hampered by gastrointestinal enzymes, wide pH range, mucus and mucosal layers, which limit insulin oral bioavailability to ≤2 %. Herein, we developed a simple, inexpensive and safe dual β-cyclodextrin/dialdehyde glucan-coated keratin nanoparticle (β-CD-K-IN-DG). The resulted β-CD-K-IN-DG not only gave the ultra-high insulin loading (encapsulation efficiency (98.52 %)), but also protected insulin from acid and enzymatic degradation. This β-CD-K-IN-DG had a notable hypoglycemic effect, there was almost 80 % insulin release after 4 h of incubation under hyperglycemic conditions. Ex vivo results confirmed that β-CD-K-IN-DG possessed high mucus-penetration ability. Transepithelial transport and uptake mechanism studies revealed that bypass transport pathway and endocytosis promoted β-CD-K-IN-DG entered intestinal epithelial cells, thus increased the bioavailability of insulin (12.27 %). The improved stability of insulin during in vivo transport implied that β-CD-K-IN-DG might be a potential tool for the effective oral insulin administration.

Characterization of miRNA profiling in konjac-derived exosome-like nanoparticles and elucidation of their multifaceted roles in human health

Plant-derived exosome-like nanoparticles (ELNs) have demonstrated cross-kingdom capabilities in regulating intercellular communication, facilitating drug delivery, and providing therapeutic interventions in humans. However, the functional attributes of konjac-derived ELNs (K-ELNs) remain largely unexplored. This study investigates the isolation, characterization, and functional analysis of K-ELNs, along with the profiling and differential expression analysis of associated miRNAs in both K-ELNs and Konjac tissues. K-ELNs were successfully isolated and characterized from two konjac species using ultracentrifugation, followed by Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA). Small RNA sequencing identified a total of 3,259 miRNAs across all samples. Differential expression analysis revealed significant differences in miRNA profiles between K-ELNs and tissue samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis of target genes provided insights into their roles in modulating pathways associated with diseases such as cancer and neurodegenerative disorders. Additionally, six miRNAs were selected for validation of sequencing results via RT-qPCR. The 5'RLM-RACE method was employed to validate the cleavage sites between differentially expressed miRNAs (DEMs) and their predicted target genes, further substantiating the regulatory roles of miRNAs in konjac. The findings of this study enhance our understanding of the molecular mechanisms underlying the biological functions and applications of K-ELNs, laying the groundwork for future research into their potential therapeutic roles in human health.

Anti-inflammatory Fucoidan-ConA oral insulin nanosystems for smart blood glucose regulation

The smart oral administration Insulin device has the potential to improve glycemic management. It can reduce the risk of hypoglycemia associated with exogenous Insulin (INS) therapy while also avoiding many of the disadvantages associated with subcutaneous injections. Furthermore, diabetes mellitus (DM) is an endocrine illness characterized by inflammation, and it is critical to minimize the amount of inflammatory markers in diabetic patients while maintaining average blood glucose. In this study, a responsive nanosystem vitamin B12-Fucoidan-Concanavalin A (VB12-FU-ConA NPs) with anti-inflammatory action was developed for smart oral delivery of Insulin. Con A has high sensitivity and strong specificity as a glucose-responsive material. Fucoidan has anti-inflammatory, immunomodulatory, and hypoglycemic functions, and it can bind to Con A to form a reversible complex. Under high glucose conditions, free glucose competitively binds to Con A, which swells the nanocarrier and promotes Insulin release. Furthermore, in the low pH environment of the gastrointestinal tract, positively charged VB12 and anionic fucoidan bind tightly to protect the Insulin wrapped in the carrier, and VB12 can also bind to intestinal epithelial factors to improve transit rate, thereby promoting INS absorption. In vitro tests showed that the release of nanoparticles in hyperglycemic solutions was significantly higher than the drug release in normoglycemic conditions. Oral delivery of the nanosystems dramatically lowered blood glucose levels in type I diabetic mice (T1DM) during in vivo pharmacodynamics, minimizing the risk of hypoglycemia. Blood glucose levels reached a minimum of 8.1 ± 0.4 mmol/L after 8 h. Administering the nanosystem orally notably decreased the serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in diabetic mice. The nano delivery system can be degraded and metabolized in the intestinal tract after being taken orally, demonstrating good biodegradability and biosafety. In conclusion, the present study showed that VB12-FU-ConA nanocarriers are expected to be a novel system for rationalizing blood glucose.

Recent Insights into Glucose-Responsive Concanavalin A-Based Smart Hydrogels for Controlled Insulin Delivery

Many efforts are continuously undertaken to develop glucose-sensitive biomaterials able of controlling glucose levels in the body and self-regulating insulin delivery. Hydrogels that swell or shrink as a function of the environmental free glucose content are suitable systems for monitoring blood glucose, delivering insulin doses adapted to the glucose concentration. In this context, the development of sensors based on reversible binding to glucose molecules represents a continuous challenge. Concanavalin A (Con A) is a bioactive protein isolated from sword bean plants (Canavalia ensiformis) and contains four sugar-binding sites. The high affinity for reversibly and specifically binding glucose and mannose makes Con A as a suitable natural receptor for the development of smart glucose-responsive materials. During the last few years, Con A was used to develop smart materials, such as hydrogels, microgels, nanoparticles and films, for producing glucose biosensors or drug delivery devices. This review is focused on Con A-based materials suitable in the diagnosis and therapeutics of diabetes. A brief outlook on glucose-derived theranostics of cancer is also presented.

Quality by design (QbD) approach-based development of optimized nanocarrier to achieve quality target product profile (QTPP)-targeted lymphatic delivery

Background.Insulin, commonly used for diabetes treatment, needs better ways to improve its effectiveness and safety due to its challenges with poor permeability and stability. Various system has been developed for oral peptide delivery. The non-targeted system can prevent gastric and enzymatic degradation of peptides but cannot increase the bulk transport of peptides across the membrane. However, the non-selectivity is the limitation of the existing system. Numerous carbohydrate-binding receptors overexpressed on intestinal macrophage cells (M-cells) of gut-associated lymphoid tissue. It is the most desirable site for receptor-mediated endocytosis and lymphatic drug delivery of peptides.Objective. The prime objective of the study was to fabricate mannose ligand conjugated nanoparticles (MNPs) employing a quality-by-design approach to address permeability challenges after oral administration. Herein, the study's secondary objective of this study is to identify the influencing factor for producing quality products. Considering this objective, the Lymphatic uptake of NPs was selected as a quality target product profile (QTPP), and a systematic study was conducted to identify the critical formulation attributes (CFAs) and critical process parameters (CPP) influencing critical quality attributes (CQAs). Mannosylated Chitosan concentrations (MCs) and TPP concentrations were identified as CFAs, and stirring speed was identified as CPP.Methods. MNPs were prepared by the inotropic gelation method and filled into the enteric-coated capsule to protect from acidic environments. The effect of CFAs and CPP on responses like particle size (X) and entrapment (Y) was observed by Box-Behnken design (BBD). ANOVA statistically evaluated the result to confirm a significant level (p< 0.05). The optimal conditions of NPs were obtained by constructing an overlay plot and determining the desirability value. HPLC and zeta-seizer analysis characterized the lyophilized NPs. Cell-line studies were performed to confirm the safety and M-cell targeting of NPs to enhance Insulin oral bioavailability.Results. The morphology of NPs was revealed by SEM. The developed NPs showed a nearly oval shape with the average size, surface potential, and % drug entrapment were 245.52 ± 3.37 nm, 22.12 ± 2.13 mV, and 76.15 ± 1.3%, respectively. MTT assay result exhibited that MNPs safe and Confocal imaging inference that NPs selectively uptake by the M-cell.Conclusion. BBD experimental design enables the effective formulation of optimized NPs. The statistical analysis estimated a clear assessment of the significance of the process and formulation variable. Cell line study confirms that NPs are safe and effectively uptake by the cell.

Advances in the construction and application of konjac glucomannan-based delivery systems

Konjac glucomannan (KGM) has been widely used to deliver bioactive components due to its naturalness, non-toxicity, excellent biodegradability, biocompatibility, and other characteristics. This review presents an overview of konjac glucomannan as a matrix, and the types of konjac glucomannan-based delivery systems (such as hydrogels, food packaging films, microencapsulation, emulsions, nanomicelles) and their construction methods are introduced in detail. Furthermore, taking polyphenol compounds, probiotics, flavor substances, fatty acids, and other components as representatives, the applied research progress of konjac glucomannan-based delivery systems in food are summarized. Finally, the prospects for research directions in konjac glucomannan-based delivery systems are examined, thereby providing a theoretical basis for expanding the application of konjac glucomannan in other industries, such as food and medicine.

Polymeric nanoparticles (PNPs) for oral delivery of insulin

Successful oral insulin administration can considerably enhance the quality of life (QOL) of diabetes patients who must frequently take insulin injections. Oral insulin administration, on the other hand, is seriously hampered by gastrointestinal enzymes, wide pH range, mucus and mucosal layers, which limit insulin oral bioavailability to ≤ 2%. Therefore, a large number of technological solutions have been proposed to increase the oral bioavailability of insulin, in which polymeric nanoparticles (PNPs) are highly promising for oral insulin delivery. The recently published research articles chosen for this review are based on applications of PNPs with strong future potential in oral insulin delivery, and do not cover all related work. In this review, we will summarize the controlled release mechanisms of oral insulin delivery, latest oral insulin delivery applications of PNPs nanocarrier, challenges and prospect. This review will serve as a guide to the future investigators who wish to engineer and study PNPs as oral insulin delivery systems.

Materials and structure of polysaccharide-based delivery carriers for oral insulin: A review

Diabetes mellitus is a chronic metabolic disease that affects >500 million patients worldwide. Subcutaneous injection of insulin is the most effective treatment at present. However, regular needle injections will cause pain, inflammation, and other adverse consequences. In recent years, significant progress has been made in non-injectable insulin preparations. Oral administration is the best way of administration due to its simplicity, convenience, and good patient compliance. However, oral insulin delivery is hindered by many physiological barriers in the gastrointestinal tract, resulting in the low relative bioavailability of direct oral insulin delivery. To improve the relative bioavailability, a variety of insulin delivery vectors have been developed. Polysaccharides are used to achieve safe and effective insulin loading due to their excellent biocompatibility and protein affinity. The functional characteristics of polysaccharide-based delivery carriers, such as pH responsiveness, mucosal adhesion, and further functionalization modifications, enhance the gastrointestinal absorption and bioavailability of insulin. This paper reviews the materials and structures of oral insulin polysaccharide-based carriers, providing ideas for further improving the relative bioavailability of oral insulin.

A Closed Loop Stimuli-Responsive Concanavalin A-Loaded Chitosan-Pluronic Hydrogel for Glucose-Responsive Delivery of Short-Acting Insulin Prototyped in RIN-5F Pancreatic Cells

The optimal treatment of diabetes (in particular, type 1 diabetes-T1D) remains a challenge. Closed-loop systems (implants/inserts) provide significant advantages for glucose responsivity and providing real-time sustained release of rapid-acting insulin. Concanavalin A (ConA), a glucose affinity agent, has been used to design closed-loop insulin delivery systems but not without significant risk of leakage of ConA from the matrices and poor mechanical strength of the hydrogels impacting longevity and control of insulin release. Therefore, this work focused on employing a thermoresponsive co-forming matrix between Pluronic F-127 (PL) and structurally robust chitosan (CHT) via EDC/NHS coupling (i.e., covalent linkage of -NH2 from CHT and ConA to the -COOH of PL). The system was characterized for its chemical structure stability and integrity (FTIR, XRD and TGA), injectability, rheological parameters and hydrogel morphology (Texture Analysis, Elastosens TM Bio2 and SEM). The prepared hydrogels demonstrated shear-thinning for injectability with a maximum force of 4.9 ± 8.3 N in a 26G needle with sol-gel transitioning from 25 to 38 °C. The apparent yield stress value of the hydrogel was determined to be 67.47 Pa. The insulin loading efficiency within the hydrogel matrix was calculated to be 46.8%. Insulin release studies revealed glucose responsiveness in simulated glycemic media (4 and 10 mg/mL) over 7 days (97%) (305 nm via fluorescence spectrophotometry). The MTT studies were performed over 72 h on RIN-5F pancreatic cells with viability results >80%. Results revealed that the thermoresponsive hydrogel is a promising alternative to current closed-loop insulin delivery systems.

Progress and prospects of polysaccharide-based nanocarriers for oral delivery of proteins/peptides

The oral route has long been recognized as the most preferred route for drug delivery as it offers high patient compliance and requires minimal expertise. Unlike small molecule drugs, the harsh environment of the gastrointestinal tract and low permeability across the intestinal epithelium make oral delivery extremely ineffective for macromolecules. Accordingly, delivery systems that are rationally constructed with suitable materials to overcome barriers to oral delivery are exceptionally promising. Among the most ideal materials are polysaccharides. Depending on the interaction between polysaccharides and proteins, the thermodynamic loading and release of proteins in the aqueous phase can be realized. Specific polysaccharides (dextran, chitosan, alginate, cellulose, etc.) endow systems with functional properties, including muco-adhesiveness, pH-responsiveness, and prevention of enzymatic degradation. Furthermore, multiple groups in polysaccharides can be modified, which gives them a variety of properties and enables them to suit specific needs. This review provides an overview of different types of polysaccharide-based nanocarriers based on different kinds of interaction forces and the influencing factors in the construction of polysaccharide-based nanocarriers. Strategies of polysaccharide-based nanocarriers to improve the bioavailability of orally administered proteins/peptides were described. Additionally, current restrictions and future trends of polysaccharide-based nanocarriers for oral delivery of proteins/peptides were also covered.

Insulin-Loaded Soybean Trypsin Inhibitor-Chitosan Nanoparticles: Preparation, Characterization, and Protective Effect Evaluation

The aim of this work was to prepare insulin-loaded nanoparticles using soybean trypsin inhibitor (STI) and chitosan (CS) as a potential coating. The nanoparticles were prepared by complex coacervation, and characterized for their particle size, polydispersity index (PDI), and encapsulation efficiency. In addition, the insulin release and enzymatic degradation of nanoparticles in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were evaluated. The results showed that the optimal conditions for preparing insulin-loaded soybean trypsin inhibitor-chitosan (INs-STI-CS) nanoparticles were as follows: CS concentration of 2.0 mg/mL, STI concentration of 1.0 mg/mL, and pH 6.0. The INs-STI-CS nanoparticles prepared at this condition had a high insulin encapsulation efficiency of 85.07%, the particle diameter size was 350 ± 5 nm, and the PDI value was 0.13. The results of the in vitro evaluation of simulated gastrointestinal digestion showed that the prepared nanoparticles could improve the stability of insulin in the gastrointestinal tract. Compared with free insulin, the insulin loaded in INs-STI-CS nanoparticles was retained at 27.71% after 10 h of digestion in the intestinal tract, while free insulin was completely digested. These findings will provide a theoretical basis for improving the stability of oral insulin in the gastrointestinal tract.

Review of Konjac Glucomannan Structure, Properties, Gelation Mechanism, and Application in Medical Biology

Konjac glucomannan (KGM) is a naturally occurring macromolecular polysaccharide that exhibits remarkable film-forming and gel-forming properties, and a high degree of biocompatibility and biodegradability. The helical structure of KGM is maintained by the acetyl group, which plays a crucial role in preserving its structural integrity. Various degradation methods, including the topological structure, can enhance the stability of KGM and improve its biological activity. Recent research has focused on modifying KGM to enhance its properties, utilizing multi-scale simulation, mechanical experiments, and biosensor research. This review presents a comprehensive overview of the structure and properties of KGM, recent advancements in non-alkali thermally irreversible gel research, and its applications in biomedical materials and related areas of research. Additionally, this review outlines prospects for future KGM research, providing valuable research ideas for follow-up experiments.

Oral konjac glucomannan for prevention of ionizing radiation-induced injury by regulating gut microbiota and increasing short chain fatty acids

Ionizing radiation-induced injury commonly happens in radiotherapy, leading to damages of the hematopoietic and gastrointestinal systems. Radioprotective medications are mainly applied in hospitals, although only injections are available and their gut protection is limited. Here, oral konjac glucomannan (KGM), a natural macromolecule and soluble dietary fiber, was used against ionizing radiation-induced injury. The mice were fed with KGM (0.4 g/kg) for 3 days or injected with a clinical medication amifostine before 6.5 Gy γ-ray whole body irradiation (WBI) or 13 Gy whole abdominal irradiation (WAI). In the WBI experiments, KGM improved blood cell recovery and bone marrow cell proliferation in the femur and spleen, though its effect was weaker than or similar to that of amifostine. In the WBI experiments, the gut protection of KGM was similar to or a little better than that of amifostine, involving regenerated crypts numbers, villus length, and gut permeability. Moreover, KGM remarkably enhanced the survival rates of WBI and WAI mice, consistent with amifostine. KGM, as a prebiotic, enhanced gut microbiota abundance, probiotic numbers, and short chain fatty acid production, maintaining gut homeostasis. Moreover, KGM inhibited the apoptosis of irradiated human intestinal epithelial cells. KGM is a promising natural macromolecule against ionizing radiation-induced injury.

Design and Evaluation of Pegylated Large 3D Pore Ferrisilicate as a Potential Insulin Protein Therapy to Treat Diabetic Mellitus

An iron-based SBA-16 mesoporous silica (ferrisilicate) with a large surface area and three-dimensional (3D) pores is explored as a potential insulin delivery vehicle with improved encapsulation and loading efficiency. Fe was incorporated into a framework of ferrisilicate using the isomorphous substitution technique for direct synthesis. Fe³⁺ species were identified using diffuse reflectance spectroscopy. The large surface area (804 m²/g), cubic pores (3.2 nm) and insulin loading were characterized using XRD, BET surface area, FTIR and TEM analyses. For pH sensitivity, the ferrisilicate was wrapped with polyethylene glycol (MW = 400 Daltons) (PEG). For comparison, Fe (10 wt%) was impregnated on a Korea Advanced Institute of Science and Technology Number 6 (KIT-6) sieve and Mesocellular Silica Foam (MSU-F). Insulin loading was optimized, and its release mechanism was studied using the dialysis membrane technique (MWCO = 14,000 Da) at physiological pH = 7.4, 6.8 and 1.2. The kinetics of the drug's release was studied using different structured/insulin nanoformulations, including Santa Barbara Amorphous materials (SBA-15, SBA-16), MSU-F, ultra-large-pore FDU-12 (ULPFDU-12) and ferrisilicates. A different insulin adsorption times (0.08-1 h), insulin/ferrisilicate ratios (0.125-1.0) and drug release rates at different pH were examined using the Korsmeyer-Peppas model. The rate of drug release and the diffusion mechanisms were obtained based on the release constant (k) and release exponent (n). The cytotoxicity of the nanoformulation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using human foreskin fibroblast (HFF-1) cells. A low cytotoxicity was observed for this nanoformulation starting at the highest concentrations used, namely, 400 and 800 μg. The hypoglycemic activity of insulin/ferrisilicate/PEG on acute administration in Wistar rats was studied using doses of 2, 5 and 10 mg/kg body weight. The developed facile ferrisilicate/PEG nanoformulation showed a high insulin encapsulation and loading capacity with pH-sensitive insulin release for potential delivery through the oral route.

pH-sensitive O-carboxymethyl chitosan/sodium alginate nanohydrogel for enhanced oral delivery of insulin

Oral drug delivery is considered the most preferred mode of treatment because of its high patient compliance and minimal invasiveness. However, the oral delivery of protein drug has been a difficult problem which restricts its application due to the unstable and inefficient penetration of protein in the gastrointestinal tract. In this study, a novel OCMC/SA nanohydrogel was prepared by using of O-carboxymethyl chitosan (OCMC) and sodium alginate (SA) to solve the problem. The OCMC/SA had a typical nanostructure, which was helpful to increase the specific surface area and enhanced the bioavailability of the drugs. OCMC/SA had a high drug loading capacity and realized passive drug targeting function by responding to the different pH value of the microenvironment. It could have a certain protective effect on drugs in strong acid circumstances, while its structure got loosed and effectively released drugs in intestinal circumstances. OCMC/SA could release the drug for >12 h, and the released insulin could maintain high activity. OCMC/SA nanohydrogel showed promising results in type 1 diabetic rats, and its pharmacological bioavailability was 6.57 %. In conclusion, this study constructed a novel OCMC/SA nanohydrogel, which had a lot of exciting characteristics and provided a new strategy for oral drug delivery.

Carbonised Human Hair Incorporated in Agar/KGM Bioscaffold for Tissue Engineering Application: Fabrication and Characterisation

Carbon derived from biomass waste usage is rising in various fields of application due to its availability, cost-effectiveness, and sustainability, but it remains limited in tissue engineering applications. Carbon derived from human hair waste was selected to fabricate a carbon-based bioscaffold (CHAK) due to its ease of collection and inexpensive synthesis procedure. The CHAK was fabricated via gelation, rapid freezing, and ethanol immersion and characterised based on their morphology, porosity, Fourier transforms infrared (FTIR), tensile strength, swelling ability, degradability, electrical conductivity, and biocompatibility using Wharton’s jelly-derived mesenchymal stem cells (WJMSCs). The addition of carbon reduced the porosity of the bioscaffold. Via FTIR analysis, the combination of carbon, agar, and KGM was compatible. Among the CHAK, the 3HC bioscaffold displayed the highest tensile strength (62.35 ± 29.12 kPa). The CHAK also showed excellent swelling and water uptake capability. All bioscaffolds demonstrated a slow degradability rate (<50%) after 28 days of incubation, while the electrical conductivity analysis showed that the 3AHC bioscaffold had the highest conductivity compared to other CHAK bioscaffolds. Our findings also showed that the CHAK bioscaffolds were biocompatible with WJMSCs. These findings showed that the CHAK bioscaffolds have potential as bioscaffolds for tissue engineering applications.

On demand regulation of blood glucose level by biocompatible oxidized starch-Con A nanogels for glucose-responsive release of exenatide

Diabetes mellitus is a long-term chronic disease characterized by abnormal high level blood glucose (BG). An artificial closed-loop system that mimics pancreatic β-cells and releases insulin on demand has potential to improve the therapeutic efficiency of diabetes. Herein, a lectin Concanavalin A modified oxidized starch nanogel was designed to regulate glucose dynamically according to different glucose concentrations. The nanogels were formed by double cross-linking the Concanavalin A and glucose units on oxidized starch via specific binding and amide bonds to achieve the high drug loading and glucose responsiveness. The results showed that oxidized starch nanogels prolonged the half-life of antidiabetic peptide drug exenatide and released it in response to high BG concentrations. It could absorb BG at a high level and maintain glucose homeostasis. Besides, the oxidized starch nanogels performed well in recovering regular BG level from hyperglycemia state and maintaining in euglycemia state that fitted in a biological rhythm. In addition, the nanogels showed high biocompatibility in vivo and could improve plasma half-life and therapeutic efficacy of exenatide. Overall, the nanogels protected peptide drugs from degradation in plasma as a glucose-responsive platform showing a high potential for peptide drugs delivery and antidiabetic therapy.

Interactions between Nanoparticles and Intestine

The use of nanoparticles (NPs) has surely grown in recent years due to their versatility, with a spectrum of applications that range from nanomedicine to the food industry. Recent research focuses on the development of NPs for the oral administration route rather than the intravenous one, placing the interactions between NPs and the intestine at the centre of the attention. This allows the NPs functionalization to exploit the different characteristics of the digestive tract, such as the different pH, the intestinal mucus layer, or the intestinal absorption capacity. On the other hand, these same characteristics can represent a problem for their complexity, also considering the potential interactions with the food matrix or the microbiota. This review intends to give a comprehensive look into three main branches of NPs delivery through the oral route: the functionalization of NPs drug carriers for systemic targets, with the case of insulin carriers as an example; NPs for the delivery of drugs locally active in the intestine, for the treatment of inflammatory bowel diseases and colon cancer; finally, the potential concerns and side effects of the accidental and uncontrolled exposure to NPs employed as food additives, with focus on E171 (titanium dioxide) and E174 (silver NPs).