Inhaled Insulin - Current Direction of Insulin Research

Emerging Technologies in Endocrine Drug Delivery: Innovations for Improved Patient Care

Recent advancements in drug delivery systems for endocrine disorders have significantly improved patient outcomes by addressing the limitations of traditional methods such as oral tablets and injections. These innovations include non-invasive alternatives like inhaled insulin, which provides rapid absorption and better patient compliance, and robotic pills that deliver drugs directly to specific gastrointestinal sites, enhancing absorption and reducing side effects. Wearable artificial pancreas systems have revolutionized diabetes management by integrating continuous glucose monitoring with insulin pumps to automate blood glucose control. These systems demonstrate superior glycemic control and reduce hypoglycemic events. Additionally, smart insulin pens enhance diabetes care through dose tracking and real-time data sharing, improving accuracy and adherence. Microneedle patches offer a minimally invasive method for transdermal drug delivery, effectively administering hormones and therapeutic peptides without the pain and inconvenience of injections. These patches dissolve after use, eliminating biohazardous waste. Implantable devices provide long-term, controlled release of medications, significantly improving adherence and glycemic control of patients with diabetes. Hydrogels also offer new drug delivery options.  This review examines these technologies' clinical efficacy, safety, advantages, and limitations, highlighting their potential to transform endocrine disorder management. Integrating advanced delivery systems marks a significant step towards personalized medicine, tailoring treatments to individual patient needs for better health outcomes.

From islet transplantation to beta-cell regeneration: an update on beta-cell-based therapeutic approaches in type 1 diabetes

INTRODUCTION

Type 1 diabetes (T1D) mellitus is an autoimmune disease in which immune cells, predominantly effector T cells, destroy insulin-secreting beta-cells. Beta-cell destruction led to various consequences ranging from retinopathy and nephropathy to neuropathy. Different strategies have been developed to achieve normoglycemia, including exogenous glucose compensation, whole pancreas transplantation, islet transplantation, and beta-cell replacement.

AREAS COVERED

The last two decades of experience have shown that indigenous glucose compensation through beta-cell regeneration and protection is a peerless method for T1D therapy. Tremendous studies have tried to find an unlimited source for beta-cell regeneration, on the one hand, and beta-cell protection against immune attack, on the other hand. Recent advances in stem cell technology, gene editing methods, and immune modulation approaches provide a unique opportunity for both beta-cell regeneration and protection.

EXPERT OPINION

Pluripotent stem cell differentiation into the beta-cell is considered an unlimited source for beta-cell regeneration. Devising engineered pancreas-specific regulatory T cells using Chimeric Antigen Receptor (CAR) technology potentiates an effective immune tolerance induction for beta-cell protection. Beta-cell regeneration using pluripotent stem cells and beta-cell protection using pancreas-specific engineered regulatory T cells promises to develop a curative protocol in T1D.

Microencapsulation for Pharmaceutical Applications: A Review

In order to improve bioavailability, stability, control release, and target delivery of active pharmaceutical ingredients (APIs), as well as to mask their bitter taste, to increase their efficacy, and to minimize their side effects, a variety of microencapsulation (including nanoencapsulation, particle size <100 nm) technologies have been widely used in the pharmaceutical industry. Commonly used microencapsulation technologies are emulsion, coacervation, extrusion, spray drying, freeze-drying, molecular inclusion, microbubbles and microsponge, fluidized bed coating, supercritical fluid encapsulation, electro spinning/spray, and polymerization. In this review, APIs are categorized by their molecular complexity: small APIs (compounds with low molecular weight, like Aspirin, Ibuprofen, and Cannabidiol), medium APIs (compounds with medium molecular weight like insulin, peptides, and nucleic acids), and living microorganisms (such as probiotics, bacteria, and bacteriophages). This article provides an overview of these microencapsulation technologies including their processes, matrix, and their recent applications in microencapsulation of APIs. Furthermore, the advantages and disadvantages of these common microencapsulation technologies in terms of improving the efficacy of APIs for pharmaceutical treatments are comprehensively analyzed. The objective is to summarize the most recent progresses on microencapsulation of APIs for enhancing their bioavailability, control release, target delivery, masking their bitter taste and stability, and thus increasing their efficacy and minimizing their side effects. At the end, future perspectives on microencapsulation for pharmaceutical applications are highlighted.

Stem cells differentiation into insulin-producing cells (IPCs): recent advances and current challenges

Type 1 diabetes mellitus (T1D) is a chronic disease characterized by an autoimmune destruction of insulin-producing β-pancreatic cells. Although many advances have been achieved in T1D treatment, current therapy strategies are often unable to maintain perfect control of glycemic levels. Several studies are searching for new and improved methodologies for expansion of β-cell cultures in vitro to increase the supply of these cells for pancreatic islets replacement therapy. A promising approach consists of differentiation of stem cells into insulin-producing cells (IPCs) in sufficient number and functional status to be transplanted. Differentiation protocols have been designed using consecutive cytokines or signaling modulator treatments, at specific dosages, to activate or inhibit the main signaling pathways that control the differentiation of induced pluripotent stem cells (iPSCs) into pancreatic β-cells. Here, we provide an overview of the current approaches and achievements in obtaining stem cell-derived β-cells and the numerous challenges, which still need to be overcome to achieve this goal. Clinical translation of stem cells-derived β-cells for efficient maintenance of long-term euglycemia remains a major issue. Therefore, research efforts have been directed to the final steps of in vitro differentiation, aiming at production of functional and mature β-cells and integration of interdisciplinary fields to generate efficient cell therapy strategies capable of reversing the clinical outcome of T1D.

The history, current state and perspectives of aerosol therapy

Nebulization is a very effective method of drug administration. This technique has been popular since ancient times when inhalation of plants rich in tropane alkaloids with spasmolytic and analgesic effects was widely used. Undoubtedly, the invention of anasthesia in the 19th century had an influence on the development of this technique. It resulted in the search for devices that facilitated anasthesia such as pulveriser or hydronium. From the second half of the 21st century, when the first DPI and MDI inhalers were launched, the constant development of aerosol therapy has been noticed. This is due to the fact that nebulization, compared with other means of medicinal substance application (such as oral and intravenous routes of administration), is safer and it exhibits a positive dose/efficacy ratio connected to the reduction of the dose. It enables drugs administration through the lung and possesses very fast onset action. Therefore, various drugs prescribed in respiratory diseases (such as corticosteroids, β-agonists, anticholinergics) are present on the market in a form of an aerosol.

Long non-coding RNA MIAT is involved in the regulation of pyroptosis in diabetic cardiomyopathy via targeting miR-214-3p

Diabetic cardiomyopathy (DCM) is one of the most common complications of diabetes without effective treatment options. Its pathogenesis is complex and remains unclear. Long non-coding RNA (lncRNA) MIAT allele has been reported to be enriched in DCM patients and activate a pyroptosis program in hypoxia-induced H9c2 cells. Thus, whether MIAT played a role in DCM pyroptosis remains to be clarified. In the study, the expression of MIAT was found elevated in the serum of diabetic patients, as well as in high-glucose induced cardiomyocytes and diabetic mice. Further, the expression levels of CASP1 and pyroptosis correlation factors (IL-1 and IL-18) were downregulated after silencing MIAT. Through modeling and validation experiments, we then confirmed that the MIAT-miR-214-3p-CASP1 axis serves as an essential point in pyroptosis of DCM mice. These results suggested that silencing MIAT would be a potential treatment strategy for DCM.

Inhalation of sustained release microparticles for the targeted treatment of respiratory diseases

Delivering drugs through inhalation for systemic and local applications has been in practice since several decades to treat various diseases. In recent times, inhalation drug delivery is becoming one of the highly focused areas of research in the pharmaceutical industry. It is being considered as one of the major portals for delivering drugs because of its wide range of advantages like requirement of low concentrations of drug to reach therapeutic efficacy, surpassing first pass metabolism and a very low incidence of side effects as compared to conventional delivery of drugs. Owing to these favorable characteristics of pulmonary drug delivery, diverse pharmaceutical formulations like liposomes, nanoparticles, and microparticles are developed through consistent efforts for delivery drugs to lungs in suitable form. However, drug-loaded microparticles have displayed various advantages over the other pharmaceutical dosage forms which give a cutting edge over other inhalational drug delivery systems. Assuring results with respect to sustained release through inhalational delivery of drug-loaded microparticles from pre-clinical studies are anticipative of similar benefits in the clinical settings. This review centralizes partly on the advantages of inhalational microparticles over other inhalational dosage forms and largely on the therapeutic applications and future perspectives of inhalable microparticle drug delivery systems.

Pulmonary Delivery of Biological Drugs

In the last decade, biological drugs have rapidly proliferated and have now become an important therapeutic modality. This is because of their high potency, high specificity and desirable safety profile. The majority of biological drugs are peptide- and protein-based therapeutics with poor oral bioavailability. They are normally administered by parenteral injection (with a very few exceptions). Pulmonary delivery is an attractive non-invasive alternative route of administration for local and systemic delivery of biologics with immense potential to treat various diseases, including diabetes, cystic fibrosis, respiratory viral infection and asthma, etc. The massive surface area and extensive vascularisation in the lungs enable rapid absorption and fast onset of action. Despite the benefits of pulmonary delivery, development of inhalable biological drug is a challenging task. There are various anatomical, physiological and immunological barriers that affect the therapeutic efficacy of inhaled formulations. This review assesses the characteristics of biological drugs and the barriers to pulmonary drug delivery. The main challenges in the formulation and inhalation devices are discussed, together with the possible strategies that can be applied to address these challenges. Current clinical developments in inhaled biological drugs for both local and systemic applications are also discussed to provide an insight for further research.

Artificial Pancreas Control Strategies Used for Type 1 Diabetes Control and Treatment: A Comprehensive Analysis

This paper presents a comprehensive survey about the fundamental components of the artificial pancreas (AP) system including insulin administration and delivery, glucose measurement (GM), and control strategies/algorithms used for type 1 diabetes mellitus (T1DM) treatment and control. Our main focus is on the T1DM that emerges due to pancreas’s failure to produce sufficient insulin due to the loss of beta cells (β-cells). We discuss various insulin administration and delivery methods including physiological methods, open-loop, and closed-loop schemes. Furthermore, we report several factors such as hyperglycemia, hypoglycemia, and many other physical factors that need to be considered while infusing insulin in human body via AP systems. We discuss three prominent control algorithms including proportional-integral- derivative (PID), fuzzy logic, and model predictive, which have been clinically evaluated and have all shown promising results. In addition, linear and non-linear insulin infusion control schemes have been formally discussed. To the best of our knowledge, this is the first work which systematically covers recent developments in the AP components with a solid foundation for future studies in the T1DM field.

The use of hydrophobic amino acids in protecting spray dried trehalose formulations against moisture-induced changes

Trehalose is commonly used as a protein stabilizer in spray dried protein formulations delivered via the pulmonary route. Spray dried trehalose formulations are highly hygroscopic, which makes them prone to deliquescence and recrystallization when exposed to moisture, leading to impairment in aerosolization performance. The main aim of this study was to investigate and compare the effect of hydrophobic amino acids (i.e. L-leucine and L-isoleucine) in enhancing aerosolization performance and in mitigating moisture-induced changes in spray dried trehalose formulations. Trehalose was spray dried with 20-60% w/w of amino acid (i.e. L-leucine or L-isoleucine). The spray dried formulations were stored at 25 °C/50% RH for 28 days. Solid state characterization and in vitro aerosolization performance studies were performed on the spray dried formulations before and after storage. The addition of 20-60% w/w of amino acid (i.e. L-leucine or L-isoleucine) improved the emitted fractions of spray dried trehalose formulations from a dry powder inhaler. However, ≥ 40% w/w of L-leucine/L-isoleucine was needed to prevent recrystallization of trehalose in the formulations when exposed to 25 °C/50% RH for 28 days. X-ray photoelectron spectroscopy (XPS) demonstrated that samples with 40-60% w/w L-isoleucine had more amino acid on the surfaces of the particles compared to their L-leucine counterparts. This may explain the greater ability of the L-isoleucine (40-60% w/w) samples to cope with elevated humidity compared to L-leucine samples of the same concentrations, as observed in the dynamic vapour sorption (DVS) studies. In conclusion, this study demonstrated that both L-leucine and L-isoleucine were effective in enhancing aerosolization performance and mitigating moisture-induced reduction in aerosolization performance in spray dried trehalose formulations. L-isoleucine proved to be superior to L-leucine in terms of its moisture protectant effect when incorporated at the same concentration in the formulations.

Mechanism of Action of Inhaled Insulin on Whole Body Glucose Metabolism in Subjects with Type 2 Diabetes Mellitus

In the current study we investigate the mechanisms of action of short acting inhaled insulin Exubera®, on hepatic glucose production (HGP), plasma glucose and free fatty acid (FFA) concentrations. 11 T2D (Type 2 Diabetes) subjects (age = 53 ± 3 years) were studied at baseline (BAS) and after 16-weeks of Exubera® treatment. At BAS and after 16-weeks subjects received: measurement of HGP (3-³H-glucose); oral glucose tolerance test (OGTT); and a 24-h plasma glucose (24-h PG) profile. At end of study (EOS) we observed a significant decrease in fasting plasma glucose (FPG, 215 ± 15 to 137 ± 11 mg/dl), 2-hour plasma glucose (2-h PG, 309 ± 9 to 264 ± 11 mg/dl), glycated hemoglobin (HbA1c, 10.3 ± 0.5% to 7.5 ± 0.3%,), mean 24-h PG profile (212 ± 17 to 141 ± 8 mg/dl), FFA fasting (665 ± 106 to 479 ± 61 μM), post-OGTT (433 ± 83 to 239 ± 28 μM), and triglyceride (213 ± 39 to 120 ± 14 mg/dl), while high density cholesterol (HDL-C) increased (35 ± 3 to 47 ± 9 mg/dl). The basal HGP decreased significantly and the insulin secretion/insulin resistance (disposition) index increased significantly. There were no episodes of hypoglycemia and no change in pulmonary function at EOS. After 16-weeks of inhaled insulin Exubera® we observed a marked improvement in glycemic control by decreasing HGP and 24-h PG profile, and decreased FFA and triglyceride concentrations.