Insulin-loaded Chitosan Nanoparticles Research Articles

De novo fabrication of oral insulin-loaded chitosan/dextrin/pectin nanospheres and their antidiabetic efficacy in streptozotocin-induced diabetic rats

Nanotechnology can offer various non-invasive and efficient alternative delivery strategies for insulin injections to enhance the quality of life of diabetic patients. The current research was aimed to fabricate a de novo oral formula of insulin-loaded chitosan nanoparticles coated with dextrin and pectin (INS-CN/DP) to improve the bioavailability and therapeutic efficiency of oral insulin. INS-CN/DP nano-formula was prepared using ionic gelation technique and characterized by XRD, FTIR, SEM, EDX, and DLS. Insulin loading capacity and entrapment efficiency (LC%, EE%), release profile, and kinetic study was conducted for INS-CN/DP nano-formula. Next, hypoglycemic and antidiabetic efficiency of INS-CN/DP nano-formula were studied in streptozotocin-induced diabetic rats by measuring fasting and postprandial glucose, the activities of carbohydrate metabolizing enzymes, liver glycogen content, and gene expression levels of glucokinase and Glucose transporter-2. Characterization results confirmed the formation of INSCN/DP nanoparticles with LC% =26.2 ± 0.56 and EE% 69.3 ± 2.75, respectively. Size average was 282.8 nm and nearly 25% of loaded insulin released after 4 hrs vs 48% for unloaded insulin. In vivo results displayed that oral administration of INS-CN/DP nanoparticles showed highly significant hypoglycemic and antidiabetic efficacy in diabetic rats compared to unloaded oral insulin. Oral INS-CN/DP nano-formula is promising alternative for insulin injections and can be suggested as non-invasive and effective diabetes therapy

Synthesis of an insulin-loaded mucoadhesive nanoparticle designed for intranasal administration: focus on new diffusion media.

Intranasal administration is a drug delivery approach to provide a non-invasive pharmacological response in the central nervous system with relatively small peripheral side effects. To improve the residence time of intranasal drug delivery systems in the nasal mucosa, mucoadhesive polymers (e.g., chitosan) can be used. Here, insulin-loaded chitosan nanoparticles were synthesized and their physiochemical properties were evaluated based on requirements of intranasal administration. The nanoparticles were spherical (a hydrodynamic diameter of 165.3nm, polydispersity index of 0.24, and zeta potential of +21.6mV) that granted mucoadhesion without any noticeable toxicity to the nasal tissue. We applied a new approach using the Krebs-Henseleit buffer solution along with simulated nasal fluid in a Franz's diffusion cell to study this intranasal drug delivery system. We used the Krebs-Henseleit buffer because of its ability to supply glucose to the cells which serves as a novel ex vivo diffusion medium to maintain the viability of the tissue during the experiment. Based on diffusion rate and histopathological endpoints, the Krebs-Henseleit buffer solution can be a substituent solution to the commonly used simulated nasal fluid for such drug delivery systems.

Controlled release of silica-coated insulin-loaded chitosan nanoparticles as a promising oral administration system

BackgroundOral insulin administration has recently become one of the most exciting research subjects. Different approaches have been carried out to get an effective oral insulin delivery system using nanotechnology. The development of a delivery system that overcomes the difficulties of oral insulin administration, achieving high stability and minimal side effects, is still an urgent need. Therefore, this study is considered one of the efforts to design a new prospective drug delivery nano-composite (silica-coated chitosan-dextran sulfate nanoparticles).MethodsChitosan-dextran sulfate nanoparticles (CS-DS NPs) were prepared via a complex coacervation method and then coated with silica. Uncoated and silica-coated CS-DS NPs were physically characterized via different techniques. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, and atomic force microscopy (AFM) have been used to investigate the chemical elements, size, morphology, and surface properties of the prepared formulations. Differential scanning calorimetry (DSC) to assess the thermal properties of formed nano-formulations. Fourier transform infrared (FT-IR) spectroscopy investigated the silica coat and chitosan interaction. The encapsulation efficiency was evaluated using high-performance liquid chromatography (HPLC) analysis. The insulin release profile of nano-formulations was performed with and without silica coat at two different pHs (5.5,7), nearly simulating the environment of the gastrointestinal tract (GIT).ResultsThe silica-coated CS-DS NPs revealed interesting physicochemical properties exemplified by suitable core particle size obtained by TEM images (145.31 ± 33.15 nm), hydrodynamic diameter (210 ± 21 nm), high stability indicated by their zeta potential value (-32 ± 3.2 mV), and adequate surface roughness assessed by AFM. The encapsulation efficiency of insulin-loaded chitosan nanoparticles (ICN) was (66.5%) higher than that of insulin-chitosan complex nanoparticles (ICCN). The silica-coated ICN demonstrated a controlled insulin release profile at pHs (5.5 and 7) compared with uncoated ICN.ConclusionThe silica-coated ICN can be an efficient candidate as a desired oral delivery system, overcoming the common obstacles of peptides and proteins delivery and achieving high stability and controlled release for further applications.

Production of high loading insulin nanoparticles suitable for oral delivery by spray drying and freeze drying techniques

Insulin nanoparticles (NPs) with high loading content have found diverse applications in different dosage forms. This work aimed to evaluate the impact of freeze-drying and spray drying process on the structures of insulin-loaded chitosan nanoparticles, with or without mannitol as cryoprotectants. We also assessed the quality of these nanoparticles by redissolving them. Before dehydration, the chitosan/sodium tripolyphosphate/insulin crosslinked nanoparticles were optimized to 318 nm of particle size, 0.18 of PDI, 99.4% of entrapment efficiency, and 25.01% of loading content. After reconstitution, all nanoparticles, except the one produced by the freeze-drying method without using mannitol, maintained their spherical particle structure. The nanoparticles dehydrated by spray drying without mannitol also showed the smallest mean particle size (376 nm) and highest loading content (25.02%) with similar entrapment efficiency (98.7%) and PDI (0.20) compared to mannitol-containing nanoparticles dehydrated by either spray drying or freeze-drying techniques. The nanoparticles dried by spray drying without mannitol also resulted in the fastest release and highest cellular uptake efficacy of insulin. This work shows that spray drying can dehydrate insulin nanoparticles without the need for cryoprotectants, creating a significant advantage in terms of greater loading capacity with lower additive requirements and operating costs as compared to conventional freeze drying approaches.

Formulation and characterisation of insulin-loaded chitosan nanoparticles capable of inducing glucose uptake in skeletal muscle cells in vitro

A successful oral protein nanocarrier needs to exhibit the following characteristics: stability in the gastrointestinal (GI) tract, drug release at specific site, overcoming high mucus turnover, mucoadhesive properties and enhanced epithelial absorption. The purpose of this research was to examine the potential of complex coacervation technique for manufacturing of insulin-loaded chitosan-Dz13Scr nanoparticles. The nanoparticles were characterized for size, polydispersity index, entrapment efficiency, drug loading capacity, zeta potential, morphology, stability and consistency of physiochemical properties. Additionally, toxicity, GI permeation, endocytosis absorption pathway, and glucose consumption capacity, were examined in cellular assays. The optimized formulation variables [0.5% of natural polymer (chitosan) and 10 μg of an oligonucleotide (Dz13Scr)] could control the physiochemical properties of nanoparticles. The complex coacervation technique used in the study could tighten the size uniformity and generate nanoparticles with high encapsulation efficiency (88%). In vitro drug release model also confirmed that the nanoparticles could withstand the acidic environment with only 13% of insulin released. The formulation could maintain its stability upon storage, promote the permeation of encapsulated insulin via paracellular absorption and endocytic pathway, and induced glucose uptake in the skeletal muscle cells. Therefore, this insulin-loaded chitosan-Dz13Scr nanoparticle is a potential drug delivery system for management of diabetes mellitus.

Formulation development, in vitro and in vivo evaluation of chitosan engineered nanoparticles for ocular delivery of insulin.

Insulin-dependent diabetic patients have to count on the administration of painful and discomforting insulin injections. However, inadequate insulin absorption and the risk of insulin level escalation in the blood are some disadvantages associated with insulin therapy. Thus, the current study intends to formulate insulin-loaded chitosan nanoparticles for refining the systemic absorption of insulin via the ocular route. Insulin-loaded chitosan nanoparticles were prepared by the ionotropic gelation method and characterized for various parameters. Optimized insulin loaded nanoparticles (C4T4I4) were positively charged with a particle size of 215 ± 2.5 nm and showed 65.89 ± 4.3% entrapment efficiency. The in vitro drug release exhibited sustained release of insulin, where 77.2 ± 2.1% of release was observed after 12 h and leads to an assumption of the non-Fickian diffusion release mechanism. The permeation study discloses good mucoadhesive and better permeation properties of insulin loaded nanoparticles compared to free Insulin. No significant difference was observed in the size of particles after six months of storage, signifying their adequate stability. Nanoparticles were found to be non-irritant to ocular tissues and exhibited prominent blood glucose level reduction in vivo. The outcomes of this study suggested that the chitosan nanoparticulate system could act as a prominent carrier system for insulin with enhanced stability and efficacy.

Biocompatibility and safety of insulin-loaded chitosan nanoparticles/ PLGA-PEG-PLGA hydrogel (ICNPH) delivered by subconjunctival injection in rats

Ocular drug delivery, specifically protein drug delivery to the posterior segment of the eye, remains a challenge. The purpose of this study was to prepare a new double-controlled drug release system (with insulin as the drug) for ocular delivery via subconjunctival injection and to investigate its ocular biocompatibility and safety. The double-controlled release system, insulin-loaded nanoparticles/PLGA-PEG-PLGA hydrogel (ICNPH) was prepared by adding insulin-loaded chitosan nanoparticles (ICN) to PLGA-PEG-PLGA hydrogel. The characteristics of the ICN were determined by dynamic light scattering and scanning electron microscopy. HPLC was used to analyze the loading content and insulin release profile of the ICNPH. The ICN were found to be globular particles with a mean diameter of 137.5 nm and 12% loading content. The sustained release of insulin from the ICNPH lasted for more than 60 days. Electroretinograms, retinal ultrastructure and microstructure, retinal cell apoptosis and glial fibrillary acidic protein expression were examined to assess retinal injury caused by the ICNPH after subconjunctival injection. The results showed no obvious damage to retinal function, structure and neurons. Therefore, the ICNPH is biocompatible and safe via subconjunctival injection, and may be a candidate for ocular drug delivery.

In vitro and in vivo study of PCL/COLL wound dressing loaded with insulin-chitosan nanoparticles on cutaneous wound healing in rats model

In the current study, insulin delivering chitosan nanoparticles were coated onto the electrospun poly (ε-caprolactone) (PCL)/Collagen (COLL) to produce a potential wound care material. Electrospun matrices were fabricated from PCL/COLL (1:1 (w/w)) solution. The insulin-loaded chitosan nanoparticles were produced by ionic gelation process and then attached onto the yarns. The dressings were investigated regarding their surface wettability, microstructure, the capacity to absorb water, water vapour permeability, mechanical properties, blood compatibility, microbial penetration, and cellular behavior. Full-thickness excisional wound model was used to assess the in vivo healing capacity of the dressings. Our data showed that after 14 days the wounds covered with PCL/COLL/Cs-Ins wound dressing could reach to nearly full wound closure compared with the sterile gauze which exhibited nearly 45% of wound size reduction. Our results suggest that fabricated scaffolds can be potentially applied in clinical practice for wound treatment.

Nanoencapsulated chitosan nanoparticles in emulsion-based oral delivery system: In vitro and in vivo evaluation of insulin loaded formulation

In this study, we aimed to develop a novel protein - nanoencapsulated system for oral administration. For this purpose, insulin was selected as the model drug. Insulin loaded chitosan nanoparticles (INS-CS-NPs) were obtained by ionic gelation between chitosan (CS) and sodium tripolyphosphate (TPP). Afterwards, as a novel strategy the nanoparticles were loaded into the inner phase of prepared water in oil microemulsion to provide sustained released, increased in vivo stability and enhanced drug absorption in the gastrointestinal tract. By this way, INS-CS-NPs encapsulated in microemulsion (INS-CS-NP-ME) was formed. The in vitro release properties of formulations with different INS:CS and CS:TPP ratios were investigated. In vitro release study in pH 2.5 revealed that insulin release was significantly low under higher CS ratios (p < 0.05). Circular dichroism analyses showed that the conformational stability of insulin was not affected from preparation process. Furthermore, in vivo experiments in Wistar Albino rat model demonstrate that INS-CS-NP-ME effectively reduced blood glucose levels over a period of 8 h after oral administration. Based on these findings, we propose that the developed INS-CS-NP-ME system can be a promising alternative dosage form for oral protein delivery.

Preparation of insulin loaded chitosan- TPP nanoparticles by ionic gelation method

In study, insulin loaded chitosan nanoparticles were prepared via ionic gelation method using cross-linking agent sodium tripolyphosphate (STPP). To have best result for the preparation of nanoparticles, a commercial chitosan with a degree of deacetylation DD of 75 % was adjusted to 85 % - 90 % which was determined by FTIR method. The obtained deacetylated chitosan was studied for the effect of pH, concentration, ratio of chitosan and STPP. Then the insulin loaded chitosan TPP nanoparticles were prepared by ionic gelation method. These nanoparticles could deliver 91.6 % insulin at pH = 3.5, with the chitosan concentration of 1 mg/mL and the chitosan:STPP ratio of 4:1. The TEMs indicate that chitosan nanoparticles were spherical in shape and the particles size was smaller than 100 nm. Investigation of FTIR and entrapment efficiency assert that insulin loaded chitosan nanopartiles have been prepared and can become a drug delivery system via oral in the future.

A study of insulin-chitosan complex nanoparticles used for oral administration

To develop insulin nanoparticles for oral administration, insulin loaded chitosan nanoparticles (ICN), insulin-chitosan complex nanoparticles (ICCN) and enteric coated insulin-chitosan complex nanoparticles (EICCN) were prepared, and their physicochemical characteristics, drug release in vitro and hypoglycemic effects on normal rats were evaluated. The particle sizes of the ICN, ICCN and EICCN were 265 ± 14, 284 ± 19 and 342 ± 23 nm, respectively, and the zeta potential of the three kinds of nanoparticles were 40.7 ± 0.7, 31.3 ± 0.4 and 34.1 ± 0.9 mv, respectively. The entrapment efficiencies of different nanoparticles were 66.8 ± 2.1, 81.3 ± 2.6 and 81.5 ± 3.1%, respectively. The accumulated percentages of release of insulin from the three kinds of nanoparticles at 2 h were 49, 34.24 and 24.9%, respectively. The bioavailabilities of oral ICN, ICCN and EICCN compared with the SC injection of an insulin solution in Wistar rats were 5.58 ± 0.7, 7.55 ± 0.9 and 8.33 ± 0.5% over 48 h, respectively. These results indicated that the insulin-chitosan complex and the enteric coating were useful to reduce the initial burst of insulin and enhance the bioavailability of oral insulin preparations.

Enhancement of nasal absorption of insulin using chitosan nanoparticles.

To investigate the potential of chitosan nanoparticles as a system for improving the systemic absorption of insulin following nasal instillation. Insulin-loaded chitosan nanoparticles were prepared by ionotropic gelation of chitosan with tripolyphosphate anions. They were characterized for their size and zeta potential by photon correlation spectroscopy and laser Doppler anemometry, respectively. Insulin loading and release was determined by the microBCA protein assay. The ability of chitosan nanoparticles to enhance the nasal absorption of insulin was investigated in a conscious rabbit model by monitoring the plasma glucose levels. Chitosan nanoparticles had a size in the range of 300-400 nm, a positive surface charge and their insulin loading can be modulated reaching values up to 55% [insulin/nanoparticles (w/w): 55/100]. Insulin association was found to be highly mediated by an ionic interaction mechanism and its release in vitro occurred rapidly in sink conditions. Chitosan nanoparticles enhanced the nasal absorption of insulin to a greater extent than an aqueous solution of chitosan. The amount and molecular weight of chitosan did not have a significant effect on insulin response. Chitosan nanoparticles are efficient vehicles for the transport of insulin through the nasal mucosa.