Transdermal delivery of CaCO3-nanoparticles containing insulin

An Ultraswelling Microneedle Device for Facile and Efficient Drug Loading and Transdermal Delivery

The advancement and extensive demand for transdermal therapies can benefit from a safe, and efficient and user-friendly transdermal technology with broad applicability in delivering various hydrophilic drugs. Here the design and proof of concept applications of an ultraswelling microneedle device that enables the facile and efficient loading and transdermal delivery of hydrophilic drugs with different molecular weights is reported. The device consists of a super-hydrophilic hydrogel microneedle array and a resin base substrate. Using a special micromolding technique that involves hydrated crosslinking and cryogenic-demolding, the microneedle part displays a rapid swelling ratio of ≈3800%, enabling the loading of drugs up to 500 kDa in molecular weight. The drug loading process using the device just involves incubating the microneedle part in a drug solution for 1 min, followed by 15 min of drying. The microneedles can easily penetrate the skin under press and detach from the base substrate under shear, thereby releasing the payload. Administration of desired therapeutic agents using the device outperformed conventional administration methods in mitigating psoriasis and eliciting immunity. This biocompatible device, capable of withstanding ethylene oxide sterilization, can enhance the efficacy and accessibility of transdermal therapies in research institutes, hospitals, and even home settings.

Current Development of Chemical Penetration Enhancers for Transdermal Insulin Delivery

The use of the transdermal delivery system has recently gained ample recognition due to the ability to deliver drug molecules across the skin membrane, serving as an alternative to conventional oral or injectable routes. Subcutaneous insulin injection is the mainstay treatment for diabetes mellitus which often leads to non-compliance among patients, especially in younger patients. Apart from its invasiveness, the long-term consequences of insulin injection cause the development of physical trauma, which includes lipohypertrophy at the site of administration, scarring, infection, and sometimes nerve damage. Hence, there is a quest for a better alternative to drug delivery that is non-invasive and easily adaptable. One of the potential solutions is the transdermal delivery method. However, the stratum corneum (the top layer of skin) is the greatest barrier in transporting large molecules like insulin. Therefore, various chemical enhancers have been proposed to promote stratum corneum permeability, or they are designed to increase the permeability of the full epidermis, such as the use of ionic liquid, peptides, chemical pre-treatment as well as packaging insulin with carriers or nanoparticles. In this review, the recent progress in the development of chemical enhancers for transdermal insulin delivery is discussed along with the possible mechanistic of action and the potential outlook on the proposed permeation approaches in comparison to other therapeutical drugs

Hard, Soft, and Hard-and-Soft Drug Delivery Carriers Based on CaCO3 and Alginate Biomaterials: Synthesis, Properties, Pharmaceutical Applications

Because free therapeutic drug molecules often have adverse effects on normal tissues, deliver scanty drug concentrations and exhibit a potentially low efficacy at pathological sites, various drug carriers have been developed for preclinical and clinical trials. Their physicochemical and toxicological properties are the subject of extensive research. Inorganic calcium carbonate particles are promising candidates as drug delivery carriers owning to their hardness, porous internal structure, high surface area, distinctive pH-sensitivity, low degradability, etc, while soft organic alginate hydrogels are also widely used because of their special advantages such as a high hydration, bio-adhesiveness, and non-antigenicity. Here, we review these two distinct substances as well as hybrid structures encompassing both types of carriers. Methods of their synthesis, fundamental properties and mechanisms of formation, and their respective applications are described. Furthermore, we summarize and compare similarities versus differences taking into account unique advantages and disadvantages of these drug delivery carriers. Moreover, rational combination of both carrier types due to their performance complementarity (yin-&yang properties: in general, yin is referred to for definiteness as hard, and yang is broadly taken as soft) is proposed to be used in the so-called hybrid carriers endowing them with even more advanced properties envisioned to be attractive for designing new drug delivery systems.

Dextran/poly-L-arginine multi-layered CaCO3-based nanosystem for vascular drug delivery

The development of heterogeneous drug delivery systems leads to innovative strategies for targeted therapy of common pathologies, such as cancer, immunological and neurological disorders. Nowadays, it is possible to choose among a great variety of nanoparticles on the basis of the needs they have to satisfy. However, a candidate for the treatment of cardiovascular pathologies is still missing. In this context, a targeted therapy implies the conceptualization of nanoparticles that take active part in the treatment of vascular pathologies. The aim of this work was to provide a method to produce multi-layered calcium carbonate (CaCO₃) nanoparticles encapsulating a model protein, bovine serum albumin, with model antibodies on their surface. CaCO₃ nanoparticles were produced by the combination of complex coacervation and mineralization and were engineered using layer-by-layer technique with a polysaccharide, dextran sulfate, and a homo-poly-amino acid, poly-L-arginine. Morphology, biocompatibility, cellular uptake, influence on cell expression of the inflammatory marker matrix metalloproteinase-9, and hemocompatibility of the nanoparticles were studied. The presence of the dextran/poly-L-arginine layers did not negatively affect the nanoparticle overall characteristics and they did not trigger proinflammatory response in vitro. Taking together all the obtained results, we consider the proposed CaCO₃ nanoparticles as a promising tool in cardiovascular field.

Polymeric nanoparticles based on carboxymethyl chitosan in combination with painless microneedle therapy systems for enhancing transdermal insulin delivery

Biodegradable nanoparticles (NPs) have been frequently used as insulin transdermal delivery vehicles due to their grand bioavailability, better encapsulation, controlled release and less toxic properties. However, the skin's barrier properties prevent insulin-loaded NP permeation at useful levels. Nowadays, microneedles have been spotlighted as novel transdermal delivery systems due to their advantages such as painlessness, efficient penetration and no hazardous residues. Herein, we introduce polymeric nanocarriers based on carboxymethyl chitosan (CMCS) for insulin delivery, combining with microneedle therapy systems, which can rapidly deliver insulin (INS) into the skin. The resulting CMCS-based nanocarriers are spherical nanoparticles with a mean size around 200 nm, which could generate supramolecular micelles to effectively encapsulate insulin (EE% = 83.78 ± 3.73%). A nanocrystalline microneedle array (6 × 6, 75/150 μm) was used to penetrate the stratum corneum (SC) for enhancing transdermal insulin delivery, while minimizing the pain sensation caused by intravenous injection. Compared with the transdermal rate of passive diffusion [2.77 ± 0.64 μg (cm-2 h-1)], the transdermal rate of the insulin-loaded NP combined with microneedle penetration shows a 4.2-fold increase [10.24 ± 1.06 μg (cm-2 h-1)] from permeation experiment in vitro. In vivo hypoglycemic experiments demonstrate the potential of using nanocarrier combination with microneedle arrays for painless insulin delivery through the skin in a clinical setting. Thus, the developed combination scheme of nanoparticles and microneedle arrays offers an effective, user-friendly, and low-toxicity option for diabetes patients requiring long-term and multiple treatments.

Advances in transdermal insulin delivery

Insulin therapy is necessary to regulate blood glucose levels for people with type 1 diabetes and commonly used in advanced type 2 diabetes. Although subcutaneous insulin administration via hypodermic injection or pump-mediated infusion is the standard route of insulin delivery, it may be associated with pain, needle phobia, and decreased adherence, as well as the risk of infection. Therefore, transdermal insulin delivery has been widely investigated as an attractive alternative to subcutaneous approaches for diabetes management in recent years. Transdermal systems designed to prevent insulin degradation and offer controlled, sustained release of insulin may be desirable for patients and lead to increased adherence and glycemic outcomes. A challenge for transdermal insulin delivery is the inefficient passive insulin absorption through the skin due to the large molecular weight of the protein drug. In this review, we focus on the different transdermal insulin delivery techniques and their respective advantages and limitations, including chemical enhancers-promoted, electrically enhanced, mechanical force-triggered, and microneedle-assisted methods.

Nanoencapsulation of benznidazole in calcium carbonate increases its selectivity to Trypanosoma cruzi

Chagas disease is a public health problem, affecting about 7 million people worldwide. Benznidazole (BZN) is the main treatment option, but it has limited effectiveness and can cause severe adverse effects. Drug delivery through nanoparticles has attracted the interest of the scientific community aiming to improve therapeutic options. The aim of this study was to evaluate the cytotoxicity of benznidazole-loaded calcium carbonate nanoparticles (BZN@CaCO3) on Trypanosoma cruzi strain Y. It was observed that BZN@CaCO3 was able to reduce the viability of epimastigote, trypomastigote and amastigote forms of T. cruzi with greater potency when compared with BZN. The amount of BZN necessary to obtain the same effect was up to 25 times smaller when loaded with CaCO3 nanoparticles. Also, it was observed that BZN@CaCO3 enhanced the selectivity index. Furthermore, the cell-death mechanism induced by both BZN and BZN@CaCO3 was evaluated, indicating that both substances caused necrosis and changed mitochondrial membrane potential.

Safety assessments of subcutaneous doses of aragonite calcium carbonate nanocrystals in rats

Calcium carbonate nanoparticles have shown promising potentials in the delivery of drugs and metabolites. There is however, a paucity of information on the safety of their intentional or accidental over exposures to biological systems and general health safety. To this end, this study aims at documenting information on the safety of subcutaneous doses of biogenic nanocrystals of aragonite polymorph of calcium carbonate derived from cockle shells (ANC) in Sprague-Dawley (SD) rats. ANC was synthesized using the top-down method, characterized using the transmission electron microscopy and field emission scanning electron microscope and its acute and repeated dose 28-day trial toxicities were evaluated in SD rats. The results showed that the homogenous 30 ± 5 nm-sized spherical pure aragonite nanocrystals were not associated with mortality in the rats. Severe clinical signs and gross and histopathological lesions, indicating organ toxicities, were recorded in the acute toxicity (29,500 mg/m²) group and the high dose (5900 mg/m²) group of the repeated dose 28-day trial. However, the medium- (590 mg/m² body weight) and low (59 mg/m²)-dose groups showed moderate to mild lesions. The relatively mild lesions observed in the low toxicity dosage group marked the safety margin of ANC in SD rats. It was concluded from this study that the toxicity of CaCO₃ was dependent on the particulate size (30 ± 5 nm) and concentration and the route of administration used.

Insulin-coated gold nanoparticles as a new concept for personalized and adjustable glucose regulation

Diabetes mellitus is a chronic metabolic disease, characterized by high blood glucose levels, affecting millions of people around the world. Currently, the main treatment for diabetes requires multiple daily injections of insulin and self-monitoring of blood glucose levels, which markedly affect patients' quality of life. In this study we present a novel strategy for controlled and prolonged glucose regulation, based on the administration of insulin-coated gold nanoparticles (INS-GNPs). We show that both intravenous and subcutaneous injection of INS-GNPs into a mouse model of type 1 diabetes decreases blood glucose levels for periods over 3 times longer than free insulin. We further showed that conjugation of insulin to GNPs prevented its rapid degradation by the insulin-degrading-enzyme, and thus allows controlled and adjustable bio-activity. Moreover, we assessed different sizes and concentrations of INS-GNPs, and found that both parameters have a critical effect in vivo, enabling specific adjustment of blood glucose levels. These findings have the potential to improve patient compliance in diabetes mellitus.

An insight into functionalized calcium based inorganic nanomaterials in biomedicine: Trends and transitions

Over the recent years the use of biocompatible and biodegradable nanoparticles in biomedicine has become a significant priority. Calcium based ceramic nanoparticles like calcium phosphate (CaP) and calcium carbonate (CaCO3) are therefore considered as attractive carriers as they are naturally present in human body with nanosize range. Their application in tissue engineering and localized controlled delivery of bioactives for bones and teeth is well established now, but recently their use has increased significantly as carrier of bioactives through other routes also. These delivery systems have become most potential alternatives to other commonly used delivery system because of their cost effectiveness, biodegradability, chemical stability, controlled and stimuli responsive behaviour. This review comprehensively covers their characteristic features, method of preparation and applications but the thrust is to focus their recent development, functionalization and use in systemic delivery. On the same platform mineralization of other nanoparticulate delivery system which has widened their application drug delivery will be discussed. The emphasis has been given on their pH dependent properties which make them excellent carriers for tumour targeting and intracellular delivery. Finally this review also attempts to discuss their drawback which limits their clinical utility.

Managing diabetes with nanomedicine: challenges and opportunities

Nanotechnology-based approaches hold substantial potential for improving the care of patients with diabetes. Nanoparticles are being developed as imaging contrast agents to assist in the early diagnosis of type 1 diabetes. Glucose nanosensors are being incorporated in implantable devices that enable more accurate and patient-friendly real-time tracking of blood glucose levels, and are also providing the basis for glucose-responsive nanoparticles that better mimic the body's physiological needs for insulin. Finally, nanotechnology is being used in non-invasive approaches to insulin delivery and to engineer more effective vaccine, cell and gene therapies for type 1 diabetes. Here, we analyse the current state of these approaches and discuss key issues for their translation to clinical practice.

An attempt to stabilize tanshinone IIA solid dispersion by the use of ternary systems with nano-CaCO3 and poloxamer 188

Background:

Tanshinone IIA (TSIIA) on solid dispersions (SDs) has thermodynamical instability of amorphous drug. Ternary solid dispersions (tSDs) can extend the stability of the amorphous form of drug. Poloxamer 188 was used as a SD carrier. Nano-CaCO₃ played an important role in adsorption of biomolecules and is being developed for a host of biotechnological applications.

Objective:

The aim of the present study was to investigate the dissolution behavior and accelerated stability of TSIIA on solid dispersions (SDs) by the use of ternary systems with nano-CaCO₃ and poloxamer 188.

Materials and Methods:

The TSIIA tSDs were prepared by a spray-drying method. First, the effect of combination of poloxamer 188 and nano-CaCO₃ on TSIIA dissolution was studied. Subsequently, a set of complementary techniques (DSC, XRPD, SEM and FTIR) was used to monitor the physical changes of TSIIA in the SDs. Finally, stability test was carried out under the conditions 40°C/75% RH for 6 months.

Results:

The characterization of tSDs by differential scanning calorimetry analysis (DSC) and X-ray powder diffraction (XRPD) showed that TSIIA was present in its amorphous form. Fourier transforms infrared spectroscopy (FTIR) suggested the presence of interactions between TSIIA and carriers in tSDs. Improvement in the dissolution rate was observed for all SDs. The stability study conducted on SDs with nano-CaCO₃ showed stable drug content and dissolution behavior, over the period of 6 months as compared with freshly prepared SDs.

Conclusion:

SDs preparation with nano-CaCO₃ and poloxamer 188 may be a promising approach to enhance the dissolution and stability of TSIIA.

Nanotechnology as a promising strategy for alternative routes of insulin delivery

Since its discovery, insulin has been used as highly specific and effective therapeutic protein to treat type 1 diabetes and later was associated to oral antidiabetic agents in the treatment of type 2 diabetes. Generally, insulin is administered parenterally. Although this route is successful, it still has several limitations, such as discomfort, pain, lipodystrophy at the injection sites and peripheral hyperinsulinemia, which may be the cause of side effects and some complications. Thus, alternative routes of administration have been developed, namely, those based on nanotechnologies. Nanoparticles, made of synthetic or natural materials, have been shown to successfully overcome the inherent barriers for insulin stability, degradation, and uptake across the gastrointestinal tract and other mucosal membranes. This review describes some of the many attempts made to develop alternative and more convenient routes for insulin delivery.

Nanoparticles in dermatology

Recent advances in the field of nanotechnology have allowed the manufacturing of elaborated nanometer-sized particles for various biomedical applications. A broad spectrum of particles, extending from various lipid nanostructures such as liposomes and solid lipid nanoparticles, to metal, nanocrystalline and polymer particles have already been tested as drug delivery systems in different animal models with remarkable results, promising an extensive commercialization in the coming years. Controlled drug release to skin and skin appendages, targeting of hair follicle-specific cell populations, transcutaneous vaccination and transdermal gene therapy are only a few of these new applications. Carrier systems of the new generation take advantage of improved skin penetration properties, depot effect with sustained drug release and of surface functionalization (e.g., the binding to specific ligands) allowing specific cellular and subcellular targeting. Drug delivery to skin by means of microparticles and nanocarriers could revolutionize the treatment of several skin disorders. However, the toxicological and environmental safety of micro- and nanoparticles has to be evaluated using specific toxicological studies prior to a wider implementation of the new technology. This review aims to give an overview of the most investigated applications of transcutaneously applied particle-based formulations in the fields of cosmetics and dermatology.

Iontophoresis-driven penetration of nanovesicles through microneedle-induced skin microchannels for enhancing transdermal delivery of insulin

The transdsermal delivery of insulin remains a significant challenge due to low permeation rates at therapeutically useful rates. We report unilamellar nanovesicles with membrane thickness of 3-5 nm and entrapment efficiency of 89.05+/-0.91%, which can be driven by iontophoresis for enhancing transdermal delivery of insulin through microneedle-induced skin microchannels. The permeation rates of insulin from positive nanovesicles driven by iontophoresis through skins with microneedle-induced microchannels were 713.3 times higher than that of its passive diffusion. The in vivo studies show that the blood glucose levels of diabetic rats induced by the positive nanovesicles driven by iontophoresis through skins with microneedle-induced microchannels are 33.3% and 28.3% of the initial levels at 4 and 6 h, which are comparable to those induced by subcutaneous injection of insulin. The fluorescence imaging validated the penetration of insulin from the nanovesicles driven by iontophoresis through skins with microchannels. The nanovesicles with charges show significant permeation ability with the assistance of physical devices including microneedles and iontophoresis. This approach offers a new strategy for non-invasive delivery of peptides with large molecular weights using nanovesicles.

Current challenges in non-invasive insulin delivery systems: a comparative review

The quest to eliminate the needle from insulin delivery and to replace it with non- or less-invasive alternative routes has driven rigorous pharmaceutical research to replace the injectable forms of insulin. Recently, various approaches have been studied involving many strategies using various technologies that have shown success in delivering insulin, which are designed to overcome the inherent barriers for insulin uptake across the gastrointestinal tract, mucosal membranes and skin. This review examines some of the many attempts made to develop alternative, more convenient routes for insulin delivery to avoid existing long-term dependence on multiple subcutaneous injections and to improve the pharmacodynamic properties of insulin. In addition, this article concentrates on the successes in this new millennium in developing potential non-invasive technologies and devices, and on major new milestones in modern insulin delivery for the effective treatment of diabetes.

Topical iodine facilitates transdermal delivery of insulin

Transdermal delivery of insulin is a non-invasive alternative to the subcutaneous injection of insulin in diabetic patients. It has been found that skin pretreatment with iodine followed by a dermal application of insulin results in reduced glucose and elevated hormone levels in the plasma. Topical iodine protects the dermally applied insulin presumably by inactivation of endogenous sulfhydryls such as glutathione and gamma glutamylcysteine which can reduce the disulfide bonds of the hormone. Thus, the effect of iodine is mediated by retaining the potency of the hormone during its penetration via the skin into the circulation. The proposed procedure might be applicable for additional disulfide-containing peptides such as calcitonin, somatostatin, oxytocin/vasopressin and their analogs.