Oral insulin delivery using nanoparticles based on microemulsions with different structure-types: optimisation and in vivo evaluation

Maleimide functionalized polycaprolactone micelles for glutathione quenching and doxorubicin delivery

High glutathione production is known to be one of the defense mechanisms by which many cancer cells survive elevated oxidative stress. By explicitly targeting glutathione in these cancer cells and diminishing its levels, oxidative stress can be intensified, ultimately triggering apoptosis or programmed cell death. Herein, we developed a novel approach by creating maleimide-functionalized polycaprolactone polymers, specifically using 2,3-diiodomaleimide functionality to reduce the level of glutathione in cancer cells. Polycaprolactone was chosen to conjugate the 2,3-diiodomaleimide functionality due to its biodegradable and biocompatible properties. The amphiphilic block copolymer was synthesized using PEG as a macroinitiator to make corresponding polymeric micelles. The resulting 2,3-diiodomaleimide-conjugated polycaprolactone micelles effectively quenched glutathione, even at low concentrations (0.01 mg mL-1). Furthermore, we loaded these micelles with the anticancer drug doxorubicin (DOX), which exhibited pH-dependent drug release. We obtained a loading capacity (LC) of 3.5% for the micelles, one of the highest LC reported among functional PCL-based micelles. Moreover, the enhanced LC doesn't affect their release profile. Cytotoxicity experiments demonstrated that empty and DOX-loaded micelles inhibited cancer cell growth, with the DOX-loaded micelles displaying the highest cytotoxicity. The ability of the polymer to quench intracellular GSH was also confirmed. This approach of attaching maleimide to polycaprolactone polymers shows promise in depleting elevated glutathione levels in cancer cells, potentially improving cancer treatment efficacy.

Oral insulin delivery: Barriers, strategies, and formulation approaches: A comprehensive review

Diabetes Mellitus is characterized by a hyperglycemic condition which can either be caused by the destruction of the beta cells or by the resistance developed against insulin in the cells. Insulin is a peptide hormone that regulates the metabolism of carbohydrates, proteins, and fats. Type 1 Diabetes Mellitus needs the use of Insulin for efficient management. However invasive methods of administration may lead to reduced adherence by the patients. Hence there is a need for a non-invasive method of administration. Oral Insulin has several merits over the conventional method including patient compliance, and reduced cost, and it also mimics endogenous insulin and hence reaches the liver by the portal vein at a higher concentration and thereby showing improved efficiency. However oral Insulin must pass through several barriers in the gastrointestinal tract. Some strategies that could be utilized to bypass these barriers include the use of permeation enhancers, absorption enhancers, use of suitable polymers, use of suitable carriers, and other agents. Several formulation types have been explored for the oral delivery of Insulin like hydrogels, capsules, tablets, and patches which have been described briefly by the article. A lot of attempts have been made for developing oral insulin delivery however none of them have been commercialized due to numerous shortcomings. Currently, there are several formulations from the companies that are still in the clinical phase, the success or failure of some is yet to be seen in the future.

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.

Nanoparticles for treatment of bovine Staphylococcus aureus mastitis

Staphylococcus aureus (S. aureus) is one of the most important zoonotic bacterial pathogens, infecting human beings and a wide range of animals, in particular, dairy cattle. Globally. S. aureus causing bovine mastitis is one of the biggest problems and an economic burden facing the dairy industry with a strong negative impact on animal welfare, productivity, and food safety. Furthermore, its smart pathogenesis, including facultative intracellular parasitism, increasingly serious antimicrobial resistance, and biofilm formation, make it challenging to be treated by conventional therapy. Therefore, the development of nanoparticles, especially liposomes, polymeric nanoparticles, solid lipid nanoparticles, nanogels, and inorganic nanoparticles, are gaining traction and excellent tools for overcoming the therapeutic difficulty accompanied by S. aureus mastitis. Therefore, in this review, the current progress and challenges of nanoparticles in enhancing the S. aureus mastitis therapy are focused stepwise. Firstly, the S. aureus treatment difficulties by the antimicrobial drugs are analyzed. Secondly, the advantages of nanoparticles in the treatment of S. aureus mastitis, including improving the penetration and accumulation of their payload drugs intracellular, decreasing the antimicrobial resistance, and preventing the biofilm formation, are also summarized. Thirdly, the progression of different types from the nanoparticles for controlling the S. aureus mastitis are provided. Finally, the difficulties that need to be solved, and future prospects of nanoparticles for S. aureus mastitis treatment are highlighted. This review will provide the readers with enough information about the challenges of the nanosystem to help them to design and fabricate more efficient nanoformulations against S. aureus infections.

Nanotechnology in Insulin Delivery for Management of Diabetes

Diabetes is a group of diseases characterized by hyperglycemia and originating from the deficiency or resistance to insulin, or both. Ultimately, the most effective treatment for patients with diabetes involves subcutaneous injections of insulin. However, this route of administration is often painful and inconvenient, as most patients will have to selfadminister it at least twice a day for the rest of their lives. Also, infection, insulin precipitation, and either lipoatrophy or lipohypertrophy are frequently observed at the site of injection. To date, several alternative routes of insulin administration have been explored, including nasal, pulmonary and oral. Although the delivery of insulin is an ideal route for diabetic patients, several limitations have to be overcome such as the rapid degradation of insulin in gastric fluid and low oral bioavailability. Numerous strategies have been carried out to improve these limited parameters such as the use of enzyme inhibitors, absorption enhancers, mucoadhesive polymers and chemical modification for receptor-mediated absorption. Also, insulin-loaded nanocarriers bypass several physiological barriers. This current review focuses on the various barriers existing in the delivery of insulin through the oral route and the strategies undertaken so far to overcome those obstacles using nanocarriers as a potential vehicle of insulin.

Lipid-based nanocarriers for oral peptide delivery

This article is aimed to overview the lipid-based nanostructures designed so far for the oral administration of peptides and proteins, and to analyze the influence of their composition and physicochemical (particle size, zeta potential) and pharmaceutical (drug loading and release) properties, on their interaction with the gastro-intestinal environment, and the subsequent PK/PD profile of the associated drugs. The ultimate goal has been to highlight and comparatively analyze the key factors that may be determinant of the success of these nanocarriers for oral peptide delivery. The article ends with some prospects on the challenges to be addressed for the intended commercial success of these delivery vehicles.

Oral delivery of diabetes peptides - Comparing standard formulations incorporating functional excipients and nanotechnologies in the translational context

While some orally delivered diabetes peptides are moving to late development with standard formulations incorporating functional excipients, the demonstration of the value of nanotechnology in clinic is still at an early stage. The goal of this review is to compare these two drug delivery approaches from a physico-chemical and a biopharmaceutical standpoint in an attempt to define how nanotechnology-based products can be differentiated from standard oral dosage forms for oral bioavailability of diabetes peptides. Points to consider in a translational approach are outlined to seize the opportunities offered by a better understanding of both the intestinal barrier and of nano-carriers designed for oral delivery.

Ionizing radiation-engineered nanogels as insulin nanocarriers for the development of a new strategy for the treatment of Alzheimer's disease

A growing body of evidence shows the protective role of insulin in Alzheimer's disease (AD). A nanogel system (NG) to deliver insulin to the brain, as a tool for the development of a new therapy for Alzheimer's Disease (AD), is designed and synthetized. A carboxyl-functionalized poly(N-vinyl pyrrolidone) nanogel system produced by ionizing radiation is chosen as substrate for the covalent attachment of insulin or fluorescent molecules relevant for its characterization. Biocompatibility and hemocompatibility of the naked carrier is demonstrated. The insulin conjugated to the NG (NG-In) is protected by protease degradation and able to bind to insulin receptor (IR), as demonstrated by immunofluorescence measurements showing colocalization of NG-In(FITC) with IR. Moreover, after binding to the receptor, NG-In is able to trigger insulin signaling via AKT activation. Neuroprotection of NG-In against dysfunction induced by amyloid β (Aβ), a peptide mainly involved in AD, is verified. Finally, the potential of NG-In to be efficiently transported across the Blood Brain Barrier (BBB) is demonstrated. All together these results indicate that the synthesized NG-In is a suitable vehicle system for insulin deliver in biomedicine and a very promising tool to develop new therapies for neurodegenerative diseases.

Nanoparticle based insulin delivery system: the next generation efficient therapy for Type 1 diabetes

Diabetic cases have increased rapidly in recent years throughout the world. Currently, for type-1 diabetes mellitus (T1DM), multiple daily insulin (MDI) injections is the most popular treatment throughout the world. At this juncture, researchers are trying to develop different insulin delivery systems, especially through oral and pulmonary route using nanocarrier based delivery system. This next generation efficient therapy for T1DM may help to improve the quality of life of diabetic patients who routinely employ insulin by the subcutaneous route. In this paper, we have depicted various next generation nanocarrier based insulin delivery systems such as chitosan-insulin nanoparticles, PLGA-insulin nanoparticles, dextran-insulin nanoparticles, polyalkylcyanoacrylated-insulin nanoparticles and solid lipid-insulin nanoparticles. Modulation of these insulin nanocarriers may lead to successful oral or pulmonary insulin nanoformulations in future clinical settings. Therefore, applications and limitations of these nanoparticles in delivering insulin to the targeted site have been thoroughly discussed.

Novel drug delivery system: an immense hope for diabetics

CONTEXT

Existing medication systems for the treatment of diabetes mellitus (DM) are inconvenient and troublesome for effective and safe delivery of drugs to the specific site. Therefore, investigations are desired to deliver antidiabetics using novel delivery approaches followed by their commercialization.

OBJECTIVE

The present review aims to provide a compilation on the latest development in the field of novel drug delivery systems (NDDSs) for antidiabetics with special emphasis on particulate, vesicular and miscellaneous systems.

METHODS

Review of literature (restricted to English language only) was done using electronic databases like Pubmed® and Scirus, i.e. published during 2005-2013. The CIMS/MIMS India Medical Drug Information eBook was used regarding available marketed formulation of antidiabetic drugs. Keywords used were "nanoparticle", "microparticle", "liposomes", "niosomes", "transdermal systems", "insulin", "antidiabetic drugs" and "novel drug delivery systems". Single inclusion was made for one article. If in vivo study was not done then article was seldom included in the manuscript.

RESULTS

The curiosity to develop NDDSs of antidiabetic drugs with special attention to the nanoparticulate system followed by microparticulate and lipid-based system is found to emerge gradually to overcome the problems associated with the conventional dosage forms and to win the confidence of end users towards the higher acceptability.

CONCLUSION

In the current scientific panorama when the area of novel drug delivery system has been recognized for its palpable benefits, unique potential of providing physical stability, sustained and site-specific drug delivery for a scheduled period of time can open new vistas for precise, safe and quality treatment of DM.

Perfluorodecalin-soluble fluorescent dyes for the monitoring of circulating nanocapsules with intravital fluorescence microscopy

Perfluorodecalin (PFD) is an established artificial oxygen carrier due to its physical capability to solve the respiratory gases oxygen and carbon dioxide. PFD-filled poly(n-butyl-cyanoacrylate) (PACA) nanocapsules are already discussed as effective artificial oxygen carriers, and their principal suitability for intravenous administration had been shown. To further elucidate their action in vivo, it is imperative to characterise their preclinical safety and particularly their biodistribution. For these purposes, intravital fluorescence microscopy would display an attractive technique in order to monitor the PACA nanocapsules in vivo, but unfortunately, it is impossible to stain the PACA nanocapsules with a fluorescent dye fulfilling special criteria required for in vivo microscopy. In order to develop such a dye, a long-chained fluorinated thiol was used to modify a BODIPY derivative that is a highly fluorescent organic compound belonging to the difluoro-boraindacene family, as well as to functionalise mesoscopic systems, such as CdSe/ZnS-quantum dots and gold nanoparticles. Furthermore, a functionalisation of porphyrin derivatives was investigated by placing divalent ions in the centre of these systems. Due to the high solubility of all synthesised dyes in PFD, it should be possible to stain PFD-filled particles in general. However, only the functionalised BODIPY derivative was suitable for in vivo monitoring of the PFD-filled PACA nanocapsules.

Emerging micro- and nanotechnology based synthetic approaches for insulin delivery

Insulin is essential for type 1 and advanced type 2 diabetics to maintain blood glucose levels and prolong lives. The traditional administration requires frequent subcutaneous insulin injections that are associated with poor patient compliance, including pain, local tissue necrosis, infection, and nerve damage. Taking advantage of emerging micro- and nanotechnologies, numerous alternative strategies integrated with chemical approaches for insulin delivery have been investigated. This review outlines recent developments in the controlled delivery of insulin, including oral, nasal, pulmonary, transdermal, subcutaneous and closed-loop insulin delivery. Perspectives from new materials, formulations and devices at the micro- or nano-scales are specifically surveyed. Advantages and limitations of current delivery methods, as well as future opportunities and challenges are also discussed.

Evaluation of an oral insulin formulation in normal and diabetic rats

Aim:

As injection is not an ideal means for insulin delivery, various attempts have been made to administer insulin orally until now. The development of an oral dosage form of insulin would help diabetic patients and make the treatment more convenient. The aim of the present study is to evaluate the effectiveness of an oral insulin formulation containing polar and non-polar ingredients.

Materials and Methods:

New excipient for oral insulin administration in normal and diabetic rats was evaluated by measuring blood glucose concentrations in two groups (10 rats each) of normal and streptozotocin-induced diabetic rats. Oral insulin was administrated and blood glucose was measured by glucometer at 0, 1, 2, 3 and 4 h post-feeding. The data was compared by Student's t test.

Results:

Oral insulin formulation significantly (P<0.05) reduced blood glucose from 100 mg/dl to 33.73 mg/dl and 451.66 mg/dl to 200.83 mg/dl at 4 h in normal and diabetic rats, respectively.

Conclusion:

The novel excipient used could protect insulin from gastric and pancreatic enzymes and reduce blood glucose concentration in both healthy and diabetic rats suggesting that oral delivery of insulin is feasible in a near future.

Polymer-based oral peptide nanomedicines

Oral peptide delivery has been one of the major challenges of pharmaceutical sciences as it could lead to a great improvement of classical therapies, such as insulin, alongside making an important number of new therapies feasible. Successful oral delivery needs to fulfill two key tasks: to protect the macromolecules from degradation in the GI tract and to shuttle them across the intestinal epithelium in a safe and efficient fashion. Over the last decade, there have been numerous approaches based on the chemical modification of peptides and on the use of permeation enhancers, enzyme inhibitors and drug-delivery systems. Among the approaches developed to overcome these restrictions, the design of nanocarriers seems to be a particularly promising approach. This article is an overview on the state of the art of oral-peptide formulation strategies, with special attention to insulin delivery and the use of polymeric nanocarriers as delivery systems.

Opportunities and challenges for oral delivery of hydrophobic versus hydrophilic peptide and protein-like drugs using lipid-based technologies

Peptide and protein-like drugs are macromolecules currently produced in increasing numbers by the pharmaceutical biotechnology industry. The physicochemical properties of these molecules pose barriers to oral administration. Lipid-based drug-delivery systems have the potential to overcome these barriers and may be utilized to formulate safe, stable and efficacious oral medicines. This review outlines the design of such lipid-based technologies. The mechanisms whereby these formulations enhance the absorption of lipophilic versus hydrophilic peptide and protein-like drugs are discussed. In the case of lipophilic compounds, the advantages of lipid-based drug-delivery systems including increased solubilization, decreased intestinal efflux, decreased intracellular metabolism and possible lymphatic transport are well established as is evident from the success of Neoral® and other drug products on the market. In contrast, with respect to hydrophilic compounds, the situation is more complex and, while promising formulation approaches have been studied, issues including reproducibility of response, intersubject variability and duration of response require further optimization before commercially viable products are possible.

A review of the efficacy and safety of nanoparticle-based oral insulin delivery systems

Nanotechnology is providing new and innovative means to detect, diagnose, and treat disease. In this regard, numerous nanoparticle-based approaches have been taken in an effort to develop an effective oral insulin therapy for the treatment of diabetes. This review summarizes efficacy data from studies that have evaluated oral insulin therapies in experimental models. Also provided here is an overview of the limited safety data that have been reported in these studies. To date, the most promising approaches for nanoparticle-based oral insulin therapy appear to involve the incorporation of insulin into complex multilayered nanoparticles that are mucoadhesive, biodegradable, biocompatible, and acid protected and into nanoparticles that are designed to take advantage of the vitamin B(12) uptake pathway. It is anticipated that the continued investigation and optimization of nanoparticle-based formulations for oral delivery of insulin will lead to a much sought-after noninvasive treatment for diabetes. Such investigations also may provide insight into the use of nanoparticle-based formulations for peptide- and protein-based oral treatment of other diseases and for various food-related purposes.

New approach to hydrophobic cyanine-type photosensitizer delivery using polymeric oil-cored nanocarriers: hemolytic activity, in vitro cytotoxicity and localization in cancer cells

We report on encapsulation of cyanine IR-768 in oil-in-water (o/w) microemulsion, i.e. fabrication of templated polymeric nanocapsules as effective nanocarriers for a new generation of photodynamic agents suitable for photodynamic therapy (PDT). Discussed here are nanocapsule imaging, their in vitro biological evaluation, cyanine encapsulation potential, and the cellular localization of cyanine IR-768 delivered in the nanocapsules to MCF-7 cancer cells. Oil-cored poly(n-butyl cyanoacrylate) (PBCA) nanocapsules were prepared by interfacial polymerization in o/w microemulsions formed by the nonionics Tween 80 (polysorbate 80, polyoxyethylene 20 sorbitan monooleate), and Brij 96 (polyoxyethylene 10 oleyl ether). Iso-propyl myristate (IPM), ethyl oleate (EOl), iso-octane (IO), and oleic acid (OA) were used as the oil phases and iso-propanol (IP) and propylene glycol (PG) as the cosurfactants. Such o/w droplets, also containing hydrophobic IR-768 in the oil phase, were applied in the interfacial polymerization of n-butyl cyanoacrylate at 10 degrees C at pH 5.0. The isolated cyanine-loaded nanoparticles were visualized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), which proved their unimodal size distribution and spherical shape, with diameters dependent upon the monomer content and the template type. The entrapment efficiency of cyanine increased with increasing n-butyl cyanoacrylate concentration and varied from 65.7% to 91.7%. The results of in vitro erythrocyte hemolysis and the cell viability of breast cancer MCF-7 cells showed that the PBCA nanocapsules are quite safe carriers of IR-768 in the circulation, having a very low hemolytic potential and being non-toxic to the studied cells. Fluorescence microscopy visualized the cyanine intracellular distribution and, furthermore, demonstrated that PBCA-nanocarriers effectively delivered the IR-768 molecules to the MCF-7 doxorubicin-sensitive and -resistant cell lines. Photoirradiation of the cancer cells with entrapped photosensitizer decreased cell viability, demonstrating that this effect may be utilized in PDT.