The effect of insulin-loaded trimethylchitosan nanoparticles on rats with diabetes type I

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).

Nanophytosomes for enhancement of rutin efficacy in oral administration for diabetes treatment in streptozotocin-induced diabetic rats

Rutin is a natural antioxidant compound with several therapeutic benefits. However, the application of this bioactive compound is limited due to its low stability and bioavailability. To overcome these limitations, this study aimed to encapsulate rutin into nanophytosomes (NPs) and evaluate the therapeutic potency of this nanocarrier in streptozotocin (STZ)-induced diabetic rats. The particle size, zeta potential, and encapsulation efficiency of the prepared NPs were 72.72 nm, -22 mV, and 93.7%, respectively. The in vivo study showed that the oral administration of rutin-loaded NPs (containing 25 mg rutin/kg per day) for 4 weeks was more effective than free rutin in the control of hyperglycemia and hyperlipidemia in the STZ-induced diabetic rats. Additionally, the administration of rutin-loaded NPs regulated the activities of liver marker enzymes and the levels of total hemoglobin and glycated hemoglobin in the diabetic rats. The antioxidant defenses in the diabetic rats were increased by the administration of rutin-loaded NPs more than free rutin. Moreover, the histopathological study showed that the administration of rutin-loaded NPs restored the diabetes-induced damages in kidney, liver, and pancreas. In conclusion, encapsulation of rutin with phytosomes is an effective technique to benefit from its therapeutic potential, especially to attenuate diabetic complications.

Eudragit L-100 Capsules Aromatize and Quaternerize Chitosan for Insulin Nanoparticle Oral Delivery During Toxic Oxidative Stress in Rat Liver and Kidney

BACKGROUND

Insulin, like most peptides, is classified as a hydrophilic and macromolecular drug that is considered as a low permeable and unstable compound in the gastrointestinal (GI) tract. The acidic condition of the stomach can degrade insulin molecules. Moreover, the presence of proteolytic activities of some enzymes such as trypsin and chymotrypsin can hydrolyze amide-bonds between various amino-acids in the structures of peptides and proteins. However, due to its simplicity and high patient compliance, oral administration is the most preferred route of systemic drug delivery, and for the development of an oral delivery system, some obstacles in oral administration of peptides and proteins including low permeability and low stability of the proteins in GI should be overcome.

OBJECTIVE

In this study, the effects of orally insulin nanoparticles (INPs) prepared from quaternerized N-aryl derivatives of chitosan on the biochemical factors of the liver in diabetic rats were studied.

METHODS

INPs composed of methylated (amino benzyl) chitosan were prepared by the PEC method. Lyophilized INPs were filled in pre-clinical capsules, and the capsules were enteric-coated with Eudragit L100. Twenty Male Wistar rats were randomly divided into four groups: group1: normal control rats, group 2: diabetic rats, group 3: diabetic rats received capsules INPs(30 U/kg/day, orally), group 4: the diabetic rats received regular insulin (5 U/kg/day, subcutaneously). At the end of the treatment, serum, liver and kidney tissues were collected. Biochemical parameters in serum were measured using spectrophotometric methods. Also, oxidative stress was measured in plasma, liver and kidney. Histological studies were performed using H and E staining .

RESULTS

Biochemical parameters, and liver and kidney injury markers in serum of the diabetic rats that received INPs improved significantly compared with the diabetic group. INPs reduced oxidative toxic stress biomarkers in serum, liver and kidney of the diabetic treated group. Furthermore, a histopathological change was developed in the treated groups.

CONCLUSION

Capsulated INPs can prevent diabetic liver and oxidative kidney damages (similar regular insulin). Therefore oral administration of INPs appears to be safe. Lay Summary: Although oral route is the most preferred route of administration, but oral delivery of peptides and proteins is still a challenging issue. Diabetes Mellitus may lead to severe complications, which most of them are life-threatening. In this study, we are testing the toxicity of oral insulin nanoparticles in kidney and liver of rats. For this investigation, we will prepare insulin nanoparticles composed of a quaternized derivative of chitosan. The nanoparticles will be administered orally to rats and the level of oxidative stress in their liver and kidney will be determined. The data will be compared to the subcutaneous injection of insulin.

Molecular prospect of type-2 diabetes: Nanotechnology based diagnostics and therapeutic intervention

About ninety percent of all diabetic conditions account for T2D caused due to abnormal insulin secretion/ action or increased hepatic glucose production. Factors that contribute towards the aetiology of T2D could be well explained through biochemical, molecular, and cellular aspects. In this review, we attempt to explain the recent evolving molecular and cellular advancement associated with T2D pathophysiology. Current progress fabricated in T2D research concerning intracellular signaling cascade, inflammasome, autophagy, genetic and epigenetics changes is discretely explained in simple terms. Present available anti-diabetic therapeutic strategies commercialized and their limitations which are needed to be acknowledged are addressed in the current review. In particular, the pre-eminence of nanotechnology-based approaches to nullify the inadequacy of conventional anti-diabetic therapeutics and heterogeneous nanoparticulated systems exploited in diabetic researches are also discretely mentioned and are also listed in a tabular format in the review. Additionally, as a future prospect of nanotechnology, the review presents several strategic hypotheses to ameliorate the austerity of T2D by an engineered smart targeted nano-delivery system. In detail, an effort has been made to hypothesize novel nanotechnological based therapeutic strategies, which exploits previously described inflammasome, autophagic target points. Utilizing graphical description it is explained how a smart targeted nano-delivery system could promote β-cell growth and development by inducing the Wnt signaling pathway (inhibiting Gsk3β), inhibiting inflammasome (inhibiting NLRP3), and activating autophagic target points (protecting Atg3/Atg7 complex from oxidative stress) thereby might ameliorate the severity of T2D. Additionally, several targeting molecules associated with autophagic and epigenetic factors are also highlighted, which can be exploited in future diabetic research.

Glucose-responsive hydrogel enhances the preventive effect of insulin and liraglutide on diabetic nephropathy of rats

Diabetic nephropathy (DN) is one of the most serious complications of diabetes mellitus. The combination of insulin (Ins) with liraglutide (Lir) has a greater potential for preventing DN than monotherapy. However, the renal protective effect of the combined Ins/Lir therapy is largely compromised due to their short half-lives after subcutaneous injection. Herein, a glucose-responsive hydrogel was designed in situ forming the dynamic boronic esters bonds between phenylboronic acid-grafted γ-Polyglutamic acid (PBA-PGA) and konjac glucomannan (KGM). It was hypothesized that the KGM/PBA-PGA hydrogel as the delivery vehicle of Ins/Lir would enhance the combinational effect of the latter on preventing the DN progress. Scan electronic microscopy and rheological studies showed that KGM/PBA-PGA hydrogel displayed good glucose-responsive property. Besides, the glucose-sensitive release profile of either Ins or Lir from KGM/PBA-PGA hydrogel was uniformly displayed at hyperglycemic level. Furthermore, the preventive efficacy of KGM/PBA-PGA hydrogel incorporating insulin and liraglutide (Ins/Lir-H) on DN progress was evaluated on streptozotocin-induced rats with diabetic mellitus (DM). At 6 weeks after subcutaneous injection of Ins/Lir-H, not only the morphology of kidneys was obviously recovered as shown by ultrasonography, but also the renal hemodynamics was significantly improved. Meanwhile, the 24-h urinary protein and albumin/creatinine ratio were well modulated. Inflammation and fibrosis were also largely inhibited. Besides, the glomerular NPHS-2 was obviously elevated after treatment with Ins/Lir-H. The therapeutic mechanism of Ins/Lir-H was highly associated with the alleviation of oxidative stress and activation of autophagy. Conclusively, the better preventive effect of the combined Ins/Lir via KGM/PBA-PGA hydrogel on DN progress was demonstrated as compared with their mixed solution, suggesting KGM/PBA-PGA hydrogel might be a potential vehicle of Ins/Lir to combat the progression of DN.

N,N,N-trimethylchitosan-poly (n-butylcyanoacrylate) core-shell nanoparticles as a potential oral delivery system for acyclovir

This study investigated the feasibility of polysaccharide-coated poly(n-butyl cyanoacrylate) (PBCA) nanoparticles for oral delivery of acyclovir (ACV). PBCA nanoparticles were obtained by the emulsion polymerization method. Chitosan was chemically modified to obtain N,N,N-trimethylchitosan (TMC), which was used to coat the nanoparticles (PBCA-TMC). Nanoparticles were characterized by dynamic light scattering, zeta potential, differential scanning calorimetry (DSC), atomic force microscopy (AFM), cytotoxicity, and the effect on the transepithelial electrical resistance (TEER) of the Caco-2 cells. The size of the coated nanoparticles (296.2 nm) was significantly larger than uncoated (175.0 nm). Furthermore, PBCA nanoparticles had a negative charge (-11.7 mV), which was inverted to highly positive values (+36.5 mV) after coating. DSC analysis suggested the occurrence of the coating, which was confirmed by AFM images. The MTT assay revealed concentration-dependent cytotoxicity for the core-shell nanoparticles. Additionally, PBCA-TMC caused a significant but reversible decrease in the Caco-2 cell monolayer TEER. Entrapped ACV (PBCA-ACV-TMC), a Biopharmaceutical Classification System class III drug substance, increased approximately 3.25 times the Papp of ACV in the Caco-2 permeability assay. The nanoparticles were also able to provide in vitro ACV controlled release using media with different pH values (1.2; 6.8; 7.4). Accordingly, this new core-shell nanoparticle showed the potential to improve the oral delivery of ACV.

The effects of synthetic orally administrated insulin nanoparticles in comparison to injectable insulin on the renal function markers of type 1- diabetic rats

OBJECTIVES

Injectable insulin is the most widely used therapy in patients with type 1 diabetes which has several disadvantages. The present study was aimed to evaluate the efficacy of injectable insulin on diabetes mellitus-related complications in comparison to orally encapsulated insulin nanoparticles.

MATERIALS AND METHODS

This study involved 42 Wistar rats separated into 5 groups, including control (C), diabetic control (D), diabetic receiving regular insulin (INS), diabetic receiving encapsulated insulin nanoparticle (INP), and diabetic receiving chitosan for two months. Biochemical parameters in serum and urine were measured using spectrophotometric or ELISA methods. mRNA levels of kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated using quantitative PCR.

RESULTS

There were no significant differences between the two forms of insulin in controlling the glycemic condition (P-value>0.05), but oral INP was more effective in correcting diabetic dyslipidemia in comparison to injectable insulin (P-value<0.05). Urine volume and creatinine excretion were significantly modulated by insulin and oral INP in diabetic groups (P-value<0.05), although the effects of INP on the modulation of execration of urea, acid uric, and albumin was more dramatic. Oral INP caused a significant decrease in urine concentration of KIM-1 and NGAL as well as expression of KIM-1 in renal tissue (P-value<0.05).

CONCLUSION

Our results suggested that oral INP is more effective than injectable insulin in modulation of urine and serum diabetic-related parameters.