Recent advancement of chitosan-based nanoparticles for oral controlled delivery of insulin and other therapeutic agents

Nervous system exposure of different classes of nanoparticles: A review on potential toxicity and mechanistic studies

Nanoparticles (NPs) are generally defined as very small particles in the size range of 1-100 nm. Due to the rapid development of modern society, many new materials have been developed. The widespread use of NPs in medical applications, the food industry and the textile industry has led to an increase in NPs in the environment and the possibility of human contact, which poses a serious threat to human health. The nervous system plays a leading role in maintaining the integrity and unity of the body and maintaining a harmonious balance with the external environment. Therefore, based on two categories of organic and inorganic NPs, this paper systematically summarizes the toxic effects and mechanisms of NPs released into the nervous system. The results showed that exposure to NPs may damage the nervous system, decrease learning and cognitive ability, and affect embryonic development. Finally, a remediation scheme for NPs entering the body via the environment is also introduced. This scheme aims to reduce the neurotoxicity caused by NPs by supplementing NPs with a combination of antioxidant and anti-inflammatory compounds. The results provide a valuable reference for future research in this field.

Chitosan-based materials for dental implantology: A comprehensive review

Chitosan, a versatile biopolymer, has gained recognition in the discipline of dental implantology due to possessing salient properties. This comprehensive review explores the potential of chitosan in dental implants, focusing on its biocompatibility, bioactivity, and the various chitosan-based materials that have been utilized for dental implant therapy. The review also highlights the importance of surface treatment in dental implants to enhance osseointegration and inhibit bacterial biofilm formation. Additionally, the chemical structure, properties, and sources of chitosan are described, along with its different structural forms. The characteristics of chitosan particularly color, molecular weight, viscosity, and degree of deacetylation are discussed about their influence on its applications. This review provides valuable insights into the promising utilization of polymeric chitosan in enhancing the success and functionality of dental implants. This study highlights the potential applications of chitosan in oral implantology. Chitosan possesses various advantageous properties, including muco-adhesiveness, hemostatic action, biocompatibility, biodegradability, bioactivity, and antibacterial and antifungal activities, which enhance its uses in dental implantology. However, it has limited aqueous solubility at the physiological pH, which sometimes restricts its biological application, but this problem can be overcome by using modified chitosan or chitosan derivatives, which have also shown encouraging results. Recent research suggests that chitosan may act as a promising material for coating titanium-based implants, improving osteointegration together with antibacterial properties.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

Insulin is recognized as a crucial weapon in managing diabetes. Subcutaneous (s.c.) injections are the traditional approach for insulin administration, which usually have many limitations. Numerous alternative (non-invasive) slants through different routes have been explored by the researchers for making needle-free delivery of insulin for attaining its augmented absorption as well as bioavailability. The current review delineating numerous pros and cons of several novel approaches of non-invasive insulin delivery by overcoming many of their hurdles. Primary information on the topic was gathered by searching scholarly articles from PubMed added with extraction of data from auxiliary manuscripts. Many approaches (discussed in the article) are meant for the delivery of a safe, effective, stable, and patient friendly administration of insulin via buccal, oral, inhalational, transdermal, intranasal, ocular, vaginal and rectal routes. Few of them have proven their clinical efficacy for maintaining the glycemic levels, whereas others are under the investigational pipe line. The developed products are comprising of many advanced micro/nano composite technologies and few of them might be entering into the market in near future, thereby garnishing the hopes of millions of diabetics who are under the network of s.c. insulin injections.

Applications of Chitosan Nanoparticles in Dentistry: A Review

Recently, nanotechnology has garnered significant interest across various fields due to its emerging and diverse applications. Numerous investigators have proposed that chitosan nanoparticles (CSNPs) stand out as some of the most promising nanomaterials for facilitating various activities. Chitosan, a natural biopolymer established through the deacetylation of chitin, has been extensively studied using interdisciplinary approaches for a wide range of applications. Chitosan biomaterials exhibit distinctive attributes, including biodegradability, muco-adhesion, and biocompatibility, as well as a broad spectrum of antibacterial and antifungal properties. Furthermore, chitosan stands as the sole naturally occurring cationic polysaccharide, and it can be chemically tailored into various derivatives, depending on the intended role and utilization. The potential applications of chitosan are vast and intriguing, with many yet to be fully explored and understood. The unique characteristics of chitosan have sparked growing attentiveness in pharmaceutical industries and biomedical areas around the globe. The characteristics of chitosan like its biocompatibility, and anti-inflammatory effects hold the potential to yield promising outcomes in wound healing and periodontal care following tooth extractions. The objective of this study is to provide an overview of potential applications of chitosan in the field of dentistry.

Polymer-Based Nanostructures for Pancreatic Beta-Cell Imaging and Non-Invasive Treatment of Diabetes

Diabetes poses major economic, social, and public health challenges in all countries worldwide. Besides cardiovascular disease and microangiopathy, diabetes is a leading cause of foot ulcers and lower limb amputations. With the continued rise of diabetes prevalence, it is expected that the future burden of diabetes complications, early mortality, and disabilities will increase. The diabetes epidemic is partly caused by the current lack of clinical imaging diagnostic tools, the timely monitoring of insulin secretion and insulin-expressing cell mass (beta (β)-cells), and the lack of patients' adherence to treatment, because some drugs are not tolerated or invasively administrated. In addition to this, there is a lack of efficient topical treatment capable of stopping the progression of disabilities, in particular for treating foot ulcers. In this context, polymer-based nanostructures garnered significant interest due to their tunable physicochemical characteristics, rich diversity, and biocompatibility. This review article emphasizes the last advances and discusses the prospects in the use of polymeric materials as nanocarriers for β-cell imaging and non-invasive drug delivery of insulin and antidiabetic drugs in the management of blood glucose and foot ulcers.

The effect of insulin-loaded gold and carboxymethyl chitosan nanoparticles on gene expression of glucokinase and pyruvate kinase in rats with diabetes type 1

The goal of this study was to see how effective subcutaneous (SC) insulin is and two different types of oral insulin-loaded nanoparticles (INS) including carboxymethyl chitosan nanoparticles (CMCNPs) and gold nanoparticles (AuNPs) separately and compare their effects on glucokinase, pyruvate kinase gene expressions, and other parameters in diabetes type one male Wistar rats. Seven groups of ten male Wistar rats for each group were formed at random including four control groups (n = 10) and three treatment groups (n = 10). The control groups consisted of four control groups (10 rats for each) and three treatment groups (10 rats for each). Normal control rats were not given any treatment, as were diabetic rats that were not given any treatment, and diabetic rats that were given oral nanoparticles (CMCNPs and AuNPs). Diabetic rats were given subcutaneous insulin, oral insulin-loaded carboxymethyl chitosan nanoparticles (INS-CMCNPs), and oral insulin-loaded gold nanoparticles (INS-AuNPs). The rats were treated for the final 3 weeks of the experiment, which lasted 4 weeks. CMCNPs and AuNPs presented a promising effect on pyruvate kinase and Glucokinase gene expressions compared to subcutaneous insulin. We also discovered that conjugating insulin to CMCNPs and AuNPs protects them from the insulin-degrading enzyme, which offers managed bioavailability. Furthermore, we investigated the effects of CMCNPs and AuNPs on several parameters and discovered that both have a significant effect in vivo, which enables glucose level regulation, and improves patient organ activity for better glucose consumption. PRACTICAL APPLICATIONS: In this paper, we discussed the effect of oral INS-CMCNPs and INS-AuNPs, and compared their effects on Glucokinase and pyruvate kinase gene expressions and other biochemical parameters in diabetes type one male Wistar rats. On the other hand, we investigated the impact of oral INS and subcutaneous insulin separately on the same parameters and their effect on the histology of the liver and pancreas of diabetic rats. According to our research, as we discussed the different mechanisms of INS-CMCNPs and INS-AuNPs, they presented a promising effect compared to SC insulin. They can be used to keep oral insulin safe from the environment of the gastrointestinal system to overcome all the barriers, improve the therapeutic, and clinical outcomes of insulin by maintaining its desired concentration inside the body, ending the panic of the patient from receiving insulin by the SC injection by increasing his satisfaction with receiving accurate oral insulin doses.

Synthesis and evaluation of chitosan based controlled release nanoparticles for the delivery of ticagrelor

The aim of this contemporary work was to formulate a controlled release mucoadhesive nanoparticle formulation for enhancing the oral bioavailability of Ticagrelor (TG), a BCS class IV drug, having low oral bioavailability of about 36%. The nanoparticles can act as efficient carriers for hydrophobic drugs, due to having high surface area and hence can improve their aqueous solubility due to their hydrophilic nature. The nanoparticles (NPs) of TG were formulated using chitosan (CH) as polymer and sodium tripolyphosphate (TPP) as cross-linker, by ionic gelation technique with varying concentrations of polymer with respect to TG and TPP. Characterization of prepared nanoparticles was carried out to assess zeta potential, size, shape, entrapment efficiency (EE) and loading capacity (LC), using zeta sizer, surface morphology and chemical compatibility analysis. Drug release was observed using UV-Spectrophotometer. By increasing concentration of CH the desired size of particles (106.9 nm), zeta potential (22.6 mv) and poly dispersity index (0.364) was achieved. In vitro profiles showed a controlled and prolonged release of TG in both lower pH-1.2 and neutral pH-7.4 mediums, with effective protection of entrapped TG in simulated gastric conditions. X-ray diffraction patterns (XRD) showed the crystalline nature of formed NPs. Hence, this effort showed that hydrophobic drugs can be effectively encapsulated in nanoparticulate systems to enhance their solubility and stability, ultimately improving their bioavailability and effectiveness with better patient compliance by reducing dosing frequencies as well.

Multi-functional self-assembly nanoparticles originating from small molecule natural product for oral insulin delivery through modulating tight junctions

Background

Oral administration of insulin (INS) could be absorbed into systemic circulation only if the carrier protected it from the hostile gastrointestinal conditions. However, traditional macromolecular carriers have not totally overcome challenges in addressing these biological barriers.

Result

In this study, inspired by small molecule natural products (SMNPs), we demonstrate the multi-functional self-assembly nanoparticles (BA-Al NPs) originating from baicalin (BA) and AlCl₃ through coordination bonds and hydrogen bonds. As a novel carrier for oral insulin delivery (INS@BA-Al NPs), it displayed effective capacity in pH stimuli-responsive insulin release, intestinal mucoadhesion and transepithelial absorption enhance. Meanwhile, BA improved the paracellular permeability for insulin absorption, because of its downregulation at both mRNA and protein level on internal tight junction proteins. In vivo experiments exhibited remarkable bioavailability of INS and an ideal glucose homeostasis in the type I diabetic rat model.

Conclusion

This study offers a novel frontier of multi-functional carriers based on SMNPs with self-assembly character and bioactivity, which could be a promising strategy for diabetes therapy.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01260-9.

Recent progress in polymeric non-invasive insulin delivery

The design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail.

NANO-BIOTECHNOLOGY AND ITS INNOVATIVE PERSPECTIVE IN DIABETES MANAGEMENT

Diabetes occurs due to the imbalance of glucose in the body known as glucose homeostasis, thus leading to metabolic changes in the body. The two stages hypoglycemia or hyperglycemia classify diabetes into various categories. Various bio-nanotechnological approaches are coupled up with nano particulates, polymers, liposome, various gold plated and solid lipid particulates, regulating transcellular transport, non specific cellular uptake, and paracellular transport, leading to oral, trans-dermal , pulmonary, buccal , nasal , specific gene oriented administration to avoid the patient's non compliance with the parental routes of administration. Phytochemicals are emerging strategies for the future prospects of diabetes management.

Pectin based multi-particulate carriers for colon-specific delivery of therapeutic agents

In case of colon-specific delivery of therapeutic agents through oral route, microbial/enzyme-triggered release approach has several advantages over other approaches due to unique microbial ecosystem in the colon. Multiple-unit carriers have an edge over single-unit carriers for this purpose. Among different materials/polymers explored, pectin appears as a promising biopolymer to construct microbial-triggered colon-specific carriers. Pectin is specifically degraded by colonic enzymes but insusceptible to upper gastro-intestinal enzymes. In this article, utilization of pectin solely or in combination with other polymers and/or colonic-delivery approaches is critically discussed in detail in the context of multi-particulate systems. Several studies showed that pectin-based carriers can prevent the release of payload in the stomach but start to release in the intestine. Hence, pectin alone may construct delayed release formulation but may not be sufficient for effective colon-targeting. On the other hand, combination of pectin with other materials/polymers (e.g., chitosan and Eudragit® S-100) has demonstrated huge promise for colon-specific release of payload. Hence, smartly designed pectin-based multi-particulate carriers, especially in combination with other polymers and/or colon-targeting approaches (e.g., microbial-triggered + pH-triggered or microbial-triggered + pH-triggered + time-release or microbial-triggered + pH-triggered + pressure-based), can be successful colon-specific delivery systems. However, more clinical trials are necessary to bring this idea from bench to bedside.

The effects of dietary clinoptilolite and chitosan nanoparticles on growth, body composition, haemato-biochemical parameters, immune responses, and antioxidative status of Nile tilapia exposed to imidacloprid

This study aimed at the evaluation of the mitigating effects of dietary zeolites (ZEO) and/or chitosan nanoparticle (ChNP) on imidacloprid (IMID)-induced toxicity in Nile tilapia (Oreochromis niloticus). Fish (18.03 ± 0.01 g) were allocated into six groups; one fed on a basal diet (control) (CTR), and the other groups were fed diets supplemented with ChNPs (5 g kg^-1) and/or ZEO (20 and 40 g kg^-1) (ZEO₂₀ and ZEO₄₀) for 60 days. In the last 14 days of the experiment, all groups were exposed to a sub-lethal dose of IMID (½ of 96 h LC₅₀ = 0.0545 μg L^-1). Dietary ZEO₂₀ significantly improved all growth parameters (P ˂ 0.05), while ChNPs had no significant effects. The crude protein of the fish body was significantly increased in all groups compared to the CTR (P ˂ 0.05). No significant impacts of ChNPs, ZEO, and their interaction (P > 0.05) were noticed on the moisture, dry matter, and ash percentages. Compared to the CTR, hematocrit values were significantly decreased (P ˂ 0.05) in ChNP and ZEO₂₀ groups; meanwhile, their levels were significantly increased (P ˂ 0.05) in the ZEO₄₀ group and all combined treatments. Fish fed diets with ChNPs and/or ZEO had significant increments in the MCV values (P ˂ 0.05). Moreover, fish fed diets supplemented with ChNPs or their combination with ZEO had the lowest glucose and alkaline phosphatase levels compared with the CTR. Serum aspartate transferase levels were significantly decreased in all treated groups (P ˂ 0.05) compared to the CTR. ChNPs alone or combined with ZEO significantly exhibited the highest lysozyme and nitro blue tetrazolium values (P ˂ 0.05). On the other hand, fish in the CTR group had the highest malondialdehyde and lowest nitric oxide levels compared to the other groups. Interestingly, the lowest IMID residues in fish flesh were found in fish groups fed diet with a combination of ZEO and ChNPs. Partial or complete protection of the hepatic and splenic tissues were observed in fish group with combined treatment with ChNPs and ZEO. In conclusion, the application of ZEO and/or ChNPs in Nile tilapia diets looks to be a leading approach to mitigate the toxic impacts of IMID.

Characterization and optimization of de-esterified Tragacanth-chitosan nanocomposite as a potential carrier for oral delivery of insulin: In vitro and ex vivo studies

Oral administration of insulin is one of the most challenging topics within this area, because insulin is degraded in stomach before it enters the bloodstream. In this study, for the first time, a nano-carrier for controlled and targeted oral delivery of insulin was developed using de-esterified Tragacanth and chitosan. The fabricated nanoparticles were synthesized using coacervation technique and their properties were optimized using response surface methodology. The effect of experimental variables on the particle size and loading efficiency was examined. In addition, the interactions between components were analyzed using Fourier transform infrared. The thermal stability of nanoparticles was studied by thermal gravimetric analysis. The insulin loading efficiency was measured and in vitro release profile and ex vivo insulin permeability was determined. Optimized nanoparticles showed spherical shape with a size less than 200 nm and zeta potential of +17 mV. Owing to their nanoscale dimensions and mucoadhesiveness, nanoparticles were synthesized using medium molecular weight of Chitosan. The insulin loading efficacy for the system was 6.4%, released under simulated gastrointestinal conditions in a pH-dependent manner. Based on all of the obtained results, it can be concluded that these nanoparticles can potentially be utilized as a carrier for the oral insulin delivery.

Biomedical application of chitosan-based nanoscale delivery systems: Potential usefulness in siRNA delivery for cancer therapy

Gene therapy is an emerging and promising strategy in cancer therapy where small interfering RNA (siRNA) system has been deployed for down-regulation of targeted gene and subsequent inhibition in cancer progression; some issues with siRNA, however, linger namely, its off-targeting property and degradation by enzymes. Nanoparticles can be applied for the encapsulation of siRNA thus enhancing its efficacy in gene silencing where chitosan (CS), a linear alkaline polysaccharide derived from chitin, with superb properties such as biodegradability, biocompatibility, stability and solubility, can play a vital role. Herein, the potential of CS nanoparticles has been discussed for the delivery of siRNA in cancer therapy; proliferation, metastasis and chemoresistance are suppressed by siRNA-loaded CS nanoparticles, especially the usage of pH-sensitive CS nanoparticles. CS nanoparticles can provide a platform for the co-delivery of siRNA and anti-tumor agents with their enhanced stability via chemical modifications. As pre-clinical experiments are in agreement with potential of CS-based nanoparticles for siRNA delivery, and these carriers possess biocompatibiliy and are safe, further studies can focus on evaluating their utilization in cancer patients.

Perspectives of gold nanoparticles and their applications in pancreatic cancer (Review)

Nanoparticles (NPs) represent a major point of interest in the scientific field, with an increasing number of studies revealing promising results. Nano-oncology is a relatively new area of research that continues to expand, revealing new perspectives in both diagnosing and treating cancer. Treating pancreatic cancer (PC) remains a major challenge, with modest positive results, thus an increasing number of studies have focused on this disease. Out of all the NPs that have been used in experimental studies, gold NPs (GNPs) appear to be the most efficient, with little systemic toxicity. This review aims to summarize the latest studies that reveal the effects that GNPs have on PC cells, focusing on different ways in which they can be used to diagnose this disease, to induce apoptosis or cause cytotoxicity in cancer cells. Although literature has limited data concerning this specific topic, the results are promising. However more studies are required until GNPs can be used in clinical practice.

Eudragit®-S100 Coated PLGA Nanoparticles for Colon Targeting of Etoricoxib: Optimization and Pharmacokinetic Assessments in Healthy Human Volunteers

Aim

Etoricoxib is a selective inhibitor of COX-2 enzyme. It is proposed as a potent anti-inflammatory drug intended for the control of irritable bowel syndrome. The current work aimed at developing etoricoxib-loaded nanoparticles for colon- targeting.

Materials and Methods

PLGA nanoparticles were developed via nano-spray drying technique. The D-optimal design was adopted for the investigation of the influence of i) DL-lactide-coglycolide (PLGA) concentration, ii) polyvinylpyrrolidone K30 (PVP K30) concentration and iii) lactide:glycolide ratio in the copolymer chain on the yield%, the encapsulation efficiency (EE%), particle size (PS) and percentage of drug release after 2h (P_2h), 4h (P_4h) and 12h (P_12h). To promote colon targeting of the systems, the best achieved system (M14) was either directly coated with poly(methacrylic acid-co-methyl methacrylate) [Eudragit^®-S100] or loaded into hard gelatin capsules and the capsules were coated with poly(methacrylic acid-co-methyl methacrylate) (E-M14C). The pharmacokinetic parameters of etoricoxib following oral administration of E-M14C in healthy volunteers were assessed relative to commercial etoricoxib tablets.

Results

M14 system was prepared using PLGA (0.5% w/v) at a lactide:glycolide ratio of 100:0, in the presence of PVP K30 (2% w/v). M14 system was nano-spherical particles of 488 nm size possessing promising yield% (63.5%) and EE% (91.2%). The percentage drug released after 2, 4 and 12 hours were 43.41%, 47.34 and 64.96%, respectively. Following M14-loading into hard gelatin capsules and coating with poly(methacrylic acid-co-methyl methacrylate) [Eudragit-S100], the respective P_2h, P_4h and P_12h were 10.1%, 28.60% and 65.45%. Significant (p < 0.05) differences between the pharmacokinetic parameter of E-M14C in comparison with the commercial product were revealed with a delay in T_max (from 2.5h to 6h), a prolongation in MRT_0-∞ (from 24.4h to 34.7h) and an increase in the relative oral bioavailability (4.23 folds).

Conclusion

E-M14C is a potential system for possible colon targeting of etoricoxib.

Effect of Genotype and Sex of the Host on the Bioavailability of Novel Albendazole Microcrystals Based on Chitosan and Cellulose Derivatives

Albendazole (ABZ), an anthelmintic compound widely used in the treatment of systemic nematode infections, is included in the list of class II drugs based on the Biopharmaceutical Classification System. ABZ has limited effectiveness due to its poor water solubility and consequent low bioavailability. Bioavailability of novel ABZ microcrystals based on hydroxyethylcellulose (S4A) or chitosan (S10A) was studied in male and female mice of two inbred lines, from the murine CBi-IGE model of trichinellosis, differing in susceptibility to this parasitosis (line CBi/L, resistant; line CBi+, susceptible). ABZ microcrystals were administered orally, and albendazole sulfoxide (ABZSO) was quantified in plasma by high-performance liquid chromatography. Mice given the microcrystals showed a significant increase in maximum plasmatic concentration (C_max) compared with those receiving pure ABZ (P < 0.01). In both genotypes, males and females given S4A had higher C_max than those receiving S10A (P < 0.05). CBi/L showed a greater C_max than CBi+ (significantly different only in females treated with S4A (P = 0.001)). CBi/L females attained a higher C_max than males (P < 0.05). No sex effect was observed for this variable in CBi+ (P > 0.05). The results of the pharmacokinetic analysis indicate that the microcrystalline formulations optimize ABZ bioavailability, both in males and females, S4A being the best system in CBi/L mice and S10A in CBi+. In summary, the microcrystals increased ABZ bioavailability, and under the conditions of this investigation, both host genotype and sex influenced the pharmacokinetic parameters measured.

How the Lack of Chitosan Characterization Precludes Implementation of the Safe-by-Design Concept

Efficacy and safety of nanomedicines based on polymeric (bio)materials will benefit from a rational implementation of a Safe-by-Design (SbD) approach throughout their development. In order to achieve this goal, however, a standardization of preparation and characterization methods and their accurate reporting is needed. Focusing on the example of chitosan, a biopolymer derived from chitin and frequently used in drug and vaccine delivery vector preparation, this review discusses the challenges still to be met and overcome prior to a successful implementation of the SbD approach to the preparation of chitosan-based protein drug delivery systems.

Cytotoxic effects of gemcitabine-loaded solid lipid nanoparticles in pancreatic cancer cells

This study investigated the cytotoxic effects of gemcitabine-loaded solid lipid nanoparticle (Gem-SLN) on the patient-derived primary pancreatic cancer cell lines (PPCL-46) and MiaPaCa-2. Different SLN formulations were prepared from glyceryl monostearate (GMS), polysorbate 80 (Tween® 80) and poloxamer 188 (Pol 188) as surfactants using a cold homogenization method. Gem-SLN was characterized for particle size and charge distribution, entrapment efficiency and loading capacity. Fourier Transform Infra-Red (FTIR) spectroscopy was used to verify Gem and SLN interaction while differential scanning calorimetry (DSC) was used to acquire thermodynamic information on Gem-SLN. Cytotoxicity studies was conducted on PPCL-46 cells and Mia-PaCa-2 cells. Among the different Gem-SLN formulations prepared, Gem-SLN₁₅ was selected based on entrapment efficiency (EE) of Gem, loading efficiency of Gem, cytotoxicity and rate of Gem release. Growth inhibition of Gem-SLN₁₅-treated PPCL-46 culture (IC₅₀ (2D) =27± 5 μM; IC₅₀ (3D) = 66 ± 2 μM) was remarkably higher than gemcitabine hydrochloride (GemHCl)-treated PPCL-46 culture (IC₅₀ (2D) =126±3 μM; IC₅₀ (3D) =241±3 μM). Similar trend of higher Gem-SLN₁₅ inhibition in MiaPaCa-2 culture was found (IC₅₀ (2D) =56±16 μM; IC₅₀ (3D) =127±4 μM) compared with GemHCl-treated Mia-PaCa-2 culture (IC₅₀ (2D) =188±46 μM; IC₅₀ (3D) =254±52 μM). The anticancer activity of Gem-SLN₁₅ was significantly more effective than GemHCl in PPCL-46 compared to Mia-PaCa-2 cancer cells. Schematic diagram for preparation of Gem-SLN through cold homogenization and methods for characterization and in-vitro studies.

Prospective insulin-based ophthalmic delivery systems for the treatment of dry eye syndrome and corneal injuries

The presence of insulin (INS) receptors on the ocular surface (OS) and lacrimal gland (LG), and the high prevalence of dry eye syndrome (DES) and corneal lesions in diabetic patients suggest that INS is relevant for OS homeostasis and wound healing. The study aims at developing delivery systems for the topical administration of INS to the OS in order to improve INS local bioavailability and evaluate the influence of the delivery systems on DES in diabetic rats (DM) (n = 05/group). Chitosan microparticles (MP), chitosan/poloxamer gel (GEL) and MP-loaded GEL (GELMP), with or without INS were developed. Formulations were instilled into the eyes of diabetic rats (DM) for 15 days and the tear fluid volume, corneal cells morphology and cornea thickness were assessed and compared with an aqueous dispersion of INS (DISP-INS). All delivery systems had pH of about 6, osmolality suitable for topical application and positive zeta potential. The MPs with or without INS had sizes close to 4 μm, spherical morphology and INS encapsulation efficiency of 77 ± 6%. DISP-INS and GELMP-INS formulations produced tear secretion amounts significantly higher than those receiving formulations containing no INS and similar to healthy animals. Cornea surface impression cytology showed that treatment with INS-delivery systems and not DISP-INS almost normalized cells morphology. Treatment with GELMP-INS increased INS by 2.5 in the LG and eyeball as compared to the groups treated with GEL-INS and MP-INS, while treatment with DISP-INS left no traces of drug in the eye after treatment termination. GEL and GELMP containing INS were also able to normalize the thickness of the corneal epithelia. In conclusion, GELMP-INS normalized tear fluid volume, corneal thickness, protected corneal cells morphology and increased ocular bioavailability of INS, making it a promising treatment strategy for DES and corneal lesions.

Optimized Preparation of Levofloxacin Loaded Polymeric Nanoparticles

In this work, poly(lactic-co-glycolic acid) (PLGA) and chitosan (CS) nanoparticles were synthesized with the purpose of encapsulating levofloxacin (LEV). A thorough study has been carried out in order to optimize the preparation of LEV-loaded polymeric nanoparticles (NPs) suitable for parenteral administration. Changes in the preparation method, in the organic solvent nature, in the pH of the aqueous phase, or in the temperature were investigated. To the authors´ knowledge, a systematic study in order to improve the LEV nanocarrier characteristics and the yield of drug encapsulation has not been carried out to date. The physicochemical characterization of the NPs, their encapsulation efficiency (EE), and the in vitro release of LEV revealed that the best formulation was the emulsion-solvent evaporation method using dichloromethane as organic solvent, which renders suitable LEV loaded PLGA NPs. The morphology of these NPs was investigated using TEM. Their antimicrobial activities against several microorganisms were determined in vitro measuring the minimum inhibitory concentration (MIC). The results show that the use of these loaded LEV PLGA nanoparticles has the advantage of the slow release of the antibiotic, which would permit an increase in the time period between administrations as well as to decrease the side effects of the drug.

Nanoparticulate-based drug delivery systems for small molecule anti-diabetic drugs: An emerging paradigm for effective therapy

Emergence of nanoparticulate drug delivery systems in diabetes has facilitated improved delivery of small molecule drugs which could dramatically improve the quality of life for diabetics. Conventional dosage forms of the anti-diabetic drugs exhibit variable/less bioavailability and short half-life, demanding frequent dosing and causing increased side-effects resulting in ineffectiveness of therapy and non-compliance with the patients. Considering the chronic nature of diabetes, nanotechnology-based approaches are more promising in terms of providing site-specific delivery of drugs with higher bioavailability and reduced dosage regimen. Nanomedicines act at the cellular and molecular levels to enhance the uptake of the drug into the cells or block the efflux mechanisms thus retaining the drug inside the cell for a longer duration of time. Many studies have hinted at the possibility of administering peptide drugs like glucagon like peptides orally by encapsulation into nanoparticles. Nanoparticles also allow further modifications including their encapsulation into microparticles, polyethylene glycol (PEG)-PEGylation- or functionalization with ligands for active targeting. Nevertheless, such remarkable benefits are fraught with their long-term safety concerns, regulatory hurdles, limitations of scale-up and ineffective patent protection which have hindered their commercialization. This review summarizes the latest advances in the area of nanoformulations as applied to the delivery of anti-diabetics. STATEMENT OF SIGNIFICANCE: The present work describes the latest advancements in the area of nanoformulations for anti-diabetic therapy along with highlighting the advantages that these nanoformulations offer at molecular level for diabetes. Although several potent orally active anti-hyperglycemic agents are available, the current challenges in efficient management of diabetes include optimization of the present therapies to ensure an optimum and stable level of glucose, and also to reduce the occurrence of long term complications associated with diabetes. Nanoformulations because of their high surface area to volume ratio provide improved efficacy, targeting their delivery to the desired site of action tends to minimize adverse effects and administration of peptide drugs by oral route is also possible by encapsulating them in nanoparticles. As we reflect on the success and failures of latest research on nanoformulations for the treatment of diabetes, it is important not to dwell on lack of FDA approvals but rather define future directions that guarantee more effective anti-diabetic treatment. In proposed review we have explored the latest advancement in anti-diabetic nanotechnology based formulations.

Advance in oral delivery systems for therapeutic protein

Oral delivery is the most common method of drug administration with high safety and good compliance for patients. However, delivering therapeutic proteins to the target site via oral route involves tremendous challenge due to unfavourable conditions like biochemical barrier, mucus barrier and epithelial barriers. According to the functional differences of various protein drug delivery systems, the recent advances in pH responsive polymer-based drug delivery system, mucoadhesive polymer-based drug delivery system, absorption enhancers-based drug delivery system and composite polymer-based delivery system all were briefly summarised in this review, which not only clarified the clinic potential of these novel drug delivery systems, but also described the way for increasing oral bioavailability of therapeutic protein.

Effect of insulin-coated trimethyl chitosan nanoparticles on IGF-1, IGF-2, and apoptosis in the hippocampus of diabetic male rats

BACKGROUND

Subcutaneous injection of insulin can lead to problems such as hypoglycemia and edema.

OBJECTIVE

The purpose of this research was to evaluate the effect of oral insulin-coated trimethyl chitosan nanoparticles on control of glycemic status, IGF-1 and IGF-2 levels, and apoptosis in the hippocampus of rats with diabetes mellitus.

METHODS

Insulin-coated trimethyl chitosan nanoparticles were prepared by the polyelectrolyte complex method (PEC) method. Insulin loading content, loading efficiency, quantity and quality of particle size were evaluated. In vivo study was performed in different treatment groups of male Wistar rats with diabetes mellitus by insulin-coated trimethyl chitosan nanoparticles or subcutaneous injection of trade insulin. The duration of diabetes was eight weeks and the treatment was started after that time and continued for another two weeks. Body weight, fasting blood glucose (FBS), hippocampal apoptosis, and immunohistochemical (IHC) protein levels of IGF-1 and IGF-2 were assessed at the end of the experiments.

RESULTS

The size and polydispersity indexes were 533 nanometers and 0.533, respectively. Insulin coated trimethyl chitosan nanoparticles showed high loading efficiency (97.67% ) and loading content (48.83% ). The spherical shape of nanoparticle was confirmed by transmission electron microscopic (TEM). The amine, amide, ether and aliphatic groups were evaluated using FT-IR spectrophotometer which represented the correctness of the insulin coated trimethyl chitosan nanoparticles. Although the apoptotic index was not changed either by insulin-coated nano-particles or commercial insulin, in vivo results showed the efficacy of insulin-coated nanoparticles as well as commercial insulin in compensated weight loss, FBS and protein levels of IGF-1 and IGF-2.

CONCLUSIONS

The present study showed the efficacy of insulin coated nanoparticle in oral route manner that can be tested in Phase I- III clinical trials. However, a behavioral study could reveal the efficacy of insulin-loaded nanoparticles in the improvement of cognitive changes through the modulation of IGF-1 and IGF-2 levels in the hippocampus.

An asymmetric chitosan scaffold for tendon tissue engineering: In vitro and in vivo evaluation with rat tendon stem/progenitor cells

The poor healing capacity and typically incomplete regeneration of injured tendons has made tendon repair as a primary clinical concern. Several methods for repairing injured tendons have been developed in the last decade. Tendon regeneration using current tissue engineering techniques requires advanced biomaterials to satisfy both microstructural and mechanical criteria. In this study, a novel chitosan (CS)-based scaffold with asymmetric structure was fabricated using a self-deposition technique. The fabricated scaffolds were assessed with regard to the microstructural and mechanical demands of cell ingrowth and the prevention of peritendinous adhesion. In vitro studies showed that rat tendon stem/progenitor cells (TSPCs) seeded onto the CS scaffold displayed higher levels of tenogenic specific genes expression and protein production. Four and six weeks after the implantation of CS scaffolds on full-site Achilles tendon defects, in vivo tendon repair was evaluated by histology, immunohistochemistry, immunofluorescence, and mechanical measurements. The production of collagen I (COL1) and collagen III (COL3) demonstrated that the CS scaffolds were capable of inducing conspicuous tenogenic differentiation, higher tenomodulin (TNMD) production, and superior phenotypic maturity, compared with the empty defect group. The introduction of TSPCs into the CS scaffold resulted in a synergistic effect on tendon regeneration and yielded better-aligned collagen fibers with elongated, spindle-shaped cells. These findings indicated that the application of TSPC-seeded CS scaffolds would be a feasible approach for tendon repair.

STATEMENT OF SIGNIFICANCE

The poor healing capacity of injured tendons and inevitable peritendinous adhesion has made tendon regeneration a clinical priority. In this study, an asymmetric chitosan scaffold was developed to encapsulate rat tendon stem/progenitor cells (TSPCs), which could induce higher levels of tenogenic specific genes and protein expression. Remarkably, the introduction of TSPCs into the asymmetric chitosan scaffold generated a synergistic effect on in vivo tendon regeneration and lead to better-aligned collagen fibers compared with asymmetric chitosan scaffold alone. This work can provide new guidelines for the structure and property design of cell-seeded scaffolds for tendon regeneration.

Preparation, characterization, and cellular uptake of resveratrol-loaded trimethyl chitosan nanoparticles

The aim of the study was to encapsulate resveratrol (RV) in trimethyl chitosan (TMC) nanoparticles cross-linked with tripolyphosphate (TPP) and/or alginate to achieve controlled release and improved cellular uptake. TMC (degree of quaternization of 78%) was prepared by reacting purified chitosan with iodomethane. Three types of RV-loaded TMC nanoparticles were prepared: TMC-TPP (TP-NPs), TMC-alginate (TA-NPs), and TMC-alginate-TPP (TAP-NPs). TA-NPs and TAP-NPs showed lower particle size and encapsulation efficiency (EE), better distribution, and more sustained release than TP-NPs due to the high molecular weight and viscous property of alginate. Caco-2 cellular uptake of RV was improved by TMC nanoencapsulation, and TP-NPs showed the highest uptake due to its significantly higher EE. Compared with TAP-NPs, TA-NPs with higher positive surface charge showed higher cellular uptake. Moreover, Caco-2 cell growth-inhibiting activity of RV was significantly increased by TMC nanoencapsulation and TP-NPs showed the significantly highest activity with a good agreement with the permeability results.

Can natural polymers assist in delivering insulin orally?

Diabetes mellitus is one of the most grave and lethal non communicable diseases. Insulin is normally used to medicate diabetes. Due to bioavailability issues, the most regular route of administration is through injection, which may pose compliance problems to treatment. The oral administration thus appears as a suitable alternative, but with several important problems. Low stability of insulin in the gastrointestinal tract and low intestinal permeation are some of the issues. Encapsulation of insulin into polymer-based particles emerges as a plausible strategy. Different encapsulation approaches and polymers have been used in this regard. Polymers with different characteristics from natural or synthetic origin have been assessed to attain this goal, with natural polymers being preferable. Natural polymers studied so far include chitosan, alginate, carrageenan, starch, pectin, casein, tragacanth, dextran, carrageenan, gelatine and cyclodextrin. While some promising knowledge and results have been gained, a polymeric-based particle system to deliver insulin orally has not been introduced onto the market yet. In this review, effectiveness of different natural polymer materials developed so far along with fabrication techniques are evaluated.

Nanodelivery: An Emerging Avenue for Nutraceuticals and Drug Delivery

Aquaculture has been globally recognized as the fastest growing food production sector which plays a major role in meeting the increasing demand for animal protein requirement. A consensus is growing that a dramatic increase in aquaculture is needed to supply future aquatic food needs. However, there are sustained problems with the aquaculture like disease outbreaks, chemical pollution, the environmental destruction, and inefficient feed utilization. These altogether raise question mark on sustainability of aquaculture. In spite of the several strategy adopted on national and international level, as improved laboratory facilities, diagnostic expertise, and control and therapeutic strategies in order to handle disease outbreaks more effectively. Aquaculture industry is under uncertainty and the progress has not matched that of the rapidly developing aquaculture sector. In order to control disease prevalence and ensure better health of system and sustainable production, the sector demand more technical innovation for the drug use, disease treatment, water quality management, production of tailored fish for suiting better health, productivity drive by epigenetic and nutrigenomic interaction, better breeding success by efficient delivery of maturation and spawning inducing agent, nutraceutical delivery for rapid growth promotion and culture time reduction, successful use of autotransgenic, and effective vaccine. Nanotechnology has a tremendous potential to revolutionize agriculture and allied fields including aquaculture and fisheries. For these multiple purposes effort, importance of nanotechnology and nanodelivery of drugs, vaccine, nutraceutical, inducing hormones, and growth-promoting anabolics open tremendous opportunity. The paper has been targeted to delineate the possible future application of nanodelivery for the aquaculture development.

Design and Concept of Polyzwitterionic Copolymer Microgel Drug Delivery Systems In Situ Loaded with Non-steroidal Anti-inflammatory Ibuprofen

Nowadays, the modern pharmaceutical investigations are directed toward obtaining of new polymer micro- and nano-sized drug delivery carriers. In this respect, the use of hydrogel carriers based on polyzwitterions (PZIs) is an opportunity in the preparation of polymer drug delivery systems with desired characteristics. This paper describes the synthesis and characterization of micro-structured p(VA-co-DMAPS) systems with different compositions in situ loaded with Ibuprofen by emulsifier-free emulsion copolymerization (EEC) in water. The mean size of the prepared microparticles was measured by SEM and particles have been visualized by AFM. The inclusion of Ibuprofen in the polyzwitterionic copolymer microgel systems was established by using DSC. In vitro drug release experiments were carried out in order to estimate the ability of the obtained microgels to modify the release of water-insoluble Ibuprofen.

Synthesis and controlled-release properties of chitosan/β-Lactoglobulin nanoparticles as carriers for oral administration of epigallocatechin gallate

A nano-sized double-walled carrier composed of chitosan and β-lactoglobulin (β-Lg) for oral administration of epigallocatechin gallate (EGCG) was developed to achieve a prolonged release of EGCG in the gastrointestinal tract. Carboxymethyl chitosan (CMC) solution was added dropwise to chitosan hydrochloride (CHC) containing EGCG to form a primary coating by ionic complexation. Subsequently, β-Lg was added to create a secondary layer by ionic gelation. The obtained EGCG-loaded chitosan/β-Lg nanoparticles had sizes between 100 and 500 nm and zeta potentials ranging from 10 to 35mV. FT-IR spectroscopy revealed a high number of hydrogen-bonding sites in the nanoparticles, which could incorporate EGCG, resulting in high encapsulation efficiency. EGCG incorporated in the primary coating was released slowly over time by diffusion from the swollen CMC-CHC matrix after the outer layer of β-Lg was degraded in the intestinal fluid. The sustained-release property makes chitosan/β-Lg nanoparticles an attractive candidate for effective delivery of EGCG.

The Cushion Method: A New Technique for the Recovery of Hydrophilic Nanocarriers

Microencapsulation of hydrophilic therapeutic agents such as proteins or nucleotides into a nanocarrier is frequently accomplished in inverse (water-in-oil) emulsions. However, the redispersion of the nanocarriers in aqueous media often involves a complicated purification process, and the redispersion usually requires additional surfactants for its colloidal stability, which is not favored for biological applications. We propose a simple, fast, and mild method to recover hydrophilic nanocarriers prepared in inverse emulsions by temporary coating of the nanocarriers with biocompatible small molecules, so that the final aqueous dispersion of the nanocarriers can be dispersed with high recovery rate, minimal aggregation, and no additional surfactants. Such a method is termed the "cushion method" and was adopted in the preparation of chitosan nanocarriers. The nanocarriers recovered with the cushion method release encapsulated peptides in a pH-responsive manner and do not require surfactants for colloidal stabilization.

Cytotoxicity and Genotoxicity in Human Embryonic Kidney Cells Exposed to Surface Modify Chitosan Nanoparticles Loaded with Curcumin

The rapid progress in the development and scientific investments of modified nanoparticles are due to their owed activity to various diseased conditions for which they are prepared. But the toxicity which they cause cannot be overlooked. The present study demonstrates the development of phosphatidylserine (PS)-coated chitosan (CS) nanoparticles (NPs) loaded with curcumin (CU), which was then investigated against human embryonic kidney cells (HEK 293) for its cytotoxic and genotoxic effect in rats. The CU-loaded CNPs (CNPs-CU) have been prepared by ionic gelation method, later which were grafted with PS. CNPs-CU and PS-CNPs-CU have been evaluated for their size, poly dispersity index, amount of drug entrapped, and in vitro CU release. CNPs-CU has an average size 167.6 ± 3.53 nm and polydispersity index (PDI) 0.115 ± 0.014, whereas PS-CNPs-CU shows average size 220 ± 3.67 nm and PDI 0.148 ± 0.019. Surface morphology of prepared NPs was confirmed by high-resolution transmission electron microscopy (HR-TEM). There was no major difference in cell viability between PS-CNPs-CU and CNPs-CU when they were exposed to HEK 293 cells at all equivalent concentrations. A series of genotoxic studies were conducted, which revealed the non-genotoxicity potential of the developed complexes. These results demonstrated that PS-CNPs-CU may be useful as potential delivery system.