Novel glucose-responsive nanoparticles based on p-hydroxyphenethyl anisate and 3-acrylamidophenylboronic acid reduce blood glucose and ameliorate diabetic nephropathy

Synthesis of multi-responsive poly(NIPA-co-DMAEMA)-PBA hydrogel nanoparticles in aqueous solution for application as glucose-sensitive insulin-releasing nanoparticles

Objectives

This study aimed to present an innovative method for synthesizing pH-thermo-glucose responsive poly(NIPA-co-DMAEMA)-PBA hydrogel nanoparticles via single-step aqueous free radical polymerization.

Methods

The synthesis process involved free radical polymerization in an aqueous solution, and the resulting nanoparticles were characterized for their physical and chemical properties by 1H NMR, Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). Insulin-loaded poly(NIPA-co-DMAEMA)-PBA hydrogel nanoparticles were prepared and evaluated for their insulin capture and release properties at different pH and temperature, in addition to different glucose concentrations, with the release profile of insulin quantitatively evaluated using the Bradford method.

Results

1H NMR results confirmed successful PBA incorporation, and DLS outcomes consistently indicated a transition to a more hydrophobic state above the Lower Critical Solution Temperature (LCST) of NIPA and DMAEMA. While pH responsiveness exhibited variation, insulin release generally increased with rising pH from acidic to neutral conditions, aligning with the anticipated augmentation of anionic PBA moieties and increased hydrogel hydrophilicity. Increased insulin release in the presence of glucose, particularly for formulations with the lowest mol % PBA, along with a slight increase for the highest mol % PBA formulation when increasing glucose from 1 to 4 mg/mL, supported the potential of this approach for nanoparticle synthesis tailored for glucose-responsive insulin release.

Conclusions

This work successfully demonstrates a novel method for synthesizing responsive hydrogel nanoparticles and underscores their potential for controlled insulin release in response to glucose concentrations. The observed pH-dependent insulin release patterns and the influence of PBA content on responsiveness highlight the versatility and promise of this nanoparticle synthesis approach for applications in glucose-responsive drug delivery systems.

Graphical abstract

Poly(NIPA) nanoparticles containing PBA moieties are normally synthesized in two or more steps in the presence of organic solvents. Here we propose a new method for the synthesis of multiresponsive hydrogel poly(NIPA-co-DMAEMA)-PBA nanoparticles in aqueous medium in a single reaction to provide a fast and effective strategy for the production of glucose-responsive multi-systems in aqueous media from free radical polymerization.

Harnessing the Power of Stimuli-Responsive Nanoparticles as an Effective Therapeutic Drug Delivery System

The quest for effective and reliable methods of delivering medications, with the aim of improving delivery of therapeutic agent to the intended location, has presented a demanding yet captivating field in biomedical research. The concept of smart drug delivery systems is an evolving therapeutic approach, serving as a model for directing drugs to specific targets or sites. These systems have been developed to specifically target and regulate the administration of therapeutic substances in a diverse array of chronic conditions, including periodontitis, diabetes, cardiac diseases, inflammatory bowel diseases, rheumatoid arthritis, and different cancers. Nevertheless, numerous comprehensive clinical trials are still required to ascertain both the immediate and enduring impacts of such nanosystems on human subjects. This review delves into the benefits of different drug delivery vehicles, aiming to enhance comprehension of their applicability in addressing present medical requirements. Additionally, it touches upon the current applications of these stimuli-reactive nanosystems in biomedicine and outlines future development prospects.

The development of nanocarriers for natural products

Natural bioactive compounds from plants exhibit substantial pharmacological potency and therapeutic value. However, the development of most plant bioactive compounds is hindered by low solubility and instability. Conventional pharmaceutical forms, such as tablets and capsules, only partially overcome these limitations, restricting their efficacy. With the recent development of nanotechnology, nanocarriers can enhance the bioavailability, stability, and precise intracellular transport of plant bioactive compounds. Researchers are increasingly integrating nanocarrier-based drug delivery systems (NDDS) into the development of natural plant compounds with significant success. Moreover, natural products benefit from nanotechnological enhancement and contribute to the innovation and optimization of nanocarriers via self-assembly, grafting modifications, and biomimetic designs. This review aims to elucidate the collaborative and reciprocal advancement achieved by integrating nanocarriers with botanical products, such as bioactive compounds, polysaccharides, proteins, and extracellular vesicles. This review underscores the salient challenges in nanomedicine, encompassing long-term safety evaluations of nanomedicine formulations, precise targeting mechanisms, biodistribution complexities, and hurdles in clinical translation. Further, this study provides new perspectives to leverage nanotechnology in promoting the development and optimization of natural plant products for nanomedical applications and guiding the progression of NDDS toward enhanced efficiency, precision, and safety. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

An oxidized dextran-composite self-healing coated magnesium scaffold reduces apoptosis to induce bone regeneration

Self-healing coatings have shown promise in controlling the degradation of scaffolds and addressing coating detachment issues. However, developing a self-healing coating for magnesium (Mg) possessing multiple biological functions in infectious environments remains a significant challenge. In this study, a self-healing coating was developed for magnesium scaffolds using oxidized dextran (OD), 3-aminopropyltriethoxysilane (APTES), and nano-hydroxyapatite (nHA) doped micro-arc oxidation (MHA), named OD-MHA/Mg. The results demonstrated that the OD-MHA coating effectively addresses coating detachment issues and controls the degradation of Mg in an infectious environment through self-healing mechanisms. Furthermore, the OD-MHA/Mg scaffold exhibits antibacterial, antioxidant, and anti-apoptotic properties, it also promotes bone repair by upregulating the expression of osteogenesis genes and proteins. The findings of this study indicate that the OD-MHA coated Mg scaffold possessing multiple biological functions presents a promising approach for addressing infectious bone defects. Additionally, the study showcases the potential of polysaccharides with multiple biological functions in facilitating tissue healing even in challenging environments.

Nanomedicines for the management of diabetic nephropathy: present progress and prospects

Diabetic nephropathy (DN) is a serious microvascular consequence of diabetes mellitus (DM), posing an encumbrance to public health worldwide. Control over the onset and progress of DN depend heavily on early detection and effective treatment. DN is a major contributor to end-stage renal disease, and a complete cure is yet to be achieved with currently available options. Though some therapeutic molecules have exhibited promise in treating DN complications, their poor solubility profile, low bioavailability, poor permeation, high therapeutic dose and associated toxicity, and low patient compliance apprehend their clinical usefulness. Recent research has indicated nano-systems as potential theranostic platforms displaying futuristic promise in the diagnosis and treatment of DN. Early and accurate diagnosis, site-specific delivery and retention by virtue of ligand conjugation, and improved pharmacokinetic profile are amongst the major advantages of nano-platforms, defining their superiority. Thus, the emergence of nanoparticles has offered fresh approaches to the possible diagnostic and therapeutic strategies regarding DN. The present review corroborates an updated overview of different types of nanocarriers regarding potential approaches for the diagnosis and therapy of DN.

The applications of functional materials-based nano-formulations in the prevention, diagnosis and treatment of chronic inflammation-related diseases

Chronic inflammation, in general, refers to systemic immune abnormalities most often caused by the environment or lifestyle, which is the basis for various skin diseases, autoimmune diseases, cardiovascular diseases, liver diseases, digestive diseases, cancer, and so on. Therapeutic strategies have focused on immunosuppression and anti-inflammation, but conventional approaches have been poor in enhancing the substantive therapeutic effect of drugs. Nanomaterials continue to attract attention for their high flexibility, durability and simplicity of preparation, as well as high profitability. Nanotechnology is used in various areas of clinical medicine, such as medical diagnosis, monitoring and treatment. However, some related problems cannot be ignored, including various cytotoxic and worsening inflammation caused by the nanomaterials themselves. This paper provides an overview of functional nanomaterial formulations for the prevention, diagnosis and treatment of chronic inflammation-related diseases, with the intention of providing some reference for the enhancement and optimization of existing therapeutic approaches.

Polymeric nanomaterial strategies to encapsulate and deliver biological drugs: points to consider between methods

Biological drugs (BDs) play an increasingly irreplaceable role in treating various diseases such as cancer, and cardiovascular and neurodegenerative diseases. The market share of BDs is increasingly promising. However, the effectiveness of BDs is currently limited due to challenges in efficient administration and delivery, and issues with stability and degradation. Thus, the field is using nanotechnology to overcome these limitations. Specifically, polymeric nanomaterials are common BD carriers due to their biocompatibility and ease of synthesis. Different strategies are available for BD transportation, but the use of core-shell encapsulation is preferable for BDs. This review discusses recent articles on manufacturing methods for encapsulating BDs in polymeric materials, including emulsification, nanoprecipitation, self-encapsulation and coaxial electrospraying. The advantages and disadvantages of each method are analysed and discussed. We also explore the impact of critical synthesis parameters on BD activity, such as sonication in emulsifications. Lastly, we provide a vision of future challenges and perspectives for scale-up production and clinical translation.

A Closed-Loop Autologous Erythrocyte-Mediated Delivery Platform for Diabetic Nephropathy Therapy

Failure to control blood glucose level (BGL) may aggravate oxidative stress and contribute to the development of diabetic nephropathy (DN). Using erythrocytes (ERs) as the carriers, a smart self-regulatory insulin (INS) release system was constructed to release INS according to changes in BGLs to improve patients' compliance and health. To overcome the limited sources of ERs and decrease the risk of transmitting infections, we developed an in vitro, closed-loop autologous ER-mediated delivery (CAER) platform, based on a commercial hemodialysis instrument modified with a glucose-responsive ER-based INS delivery system (GOx-INS@ER). After the blood was drained via a jugular vein cannula, some of the blood was pumped into the CAER platform. The INS was packed inside the autologous ERs in the INS reactor, and then their surface was modified with glucose oxidase (GOx), which acts as a glucose-activated switch. In vivo, the CAER platform showed that the BGL responsively controlled INS release in order to control hyperglycemia and maintain the BGL in the normal range for up to 3 days; plus, there was good glycemic control without the added burden of hemodialysis in DN rabbits. These results demonstrate that this closed-loop extracorporeal hemodialysis platform provides a practical approach for improving diabetes management in DN patients.