Prolonged release of metformin by SiO2 nanoparticles pellets for type II diabetes control

Advances in metformin-delivery systems for diabetes and obesity management

Metformin is a medication that is commonly prescribed to manage type 2 diabetes. It has been used for more than 60 years and is highly effective in lowering blood glucose levels. Recent studies indicate that metformin may have additional medical benefits beyond treating diabetes, revealing its potential therapeutic uses. Oral medication is commonly used to administer metformin because of its convenience and cost-effectiveness. However, there are challenges in optimizing its effectiveness. Gastrointestinal side effects and limitations in bioavailability have led to the underutilization of metformin. Innovative drug-delivery systems such as fast-dissolving tablets, micro/nanoparticle formulations, hydrogel and microneedles have been explored to optimize metformin therapy. These strategies enhance metformin dosage, targeting, bioavailability and stability, and provide personalized treatment options for improved glucose homeostasis, antiobesity and metabolic health benefits. Developing new delivery systems for metformin shows potential for improving therapeutic outcomes, broadening its applications beyond diabetes management and addressing unmet medical needs in various clinical settings. However, it is important to improve drug-delivery systems, addressing issues such as complexity, cost, biocompatibility, stability during storage and transportation, loading capacity, required technologies and biomaterials, targeting precision and regulatory approval. Addressing these limitations is crucial for effective, safe and accessible drug delivery in clinical practice. In this review, recent advances in the development and application of metformin-delivery systems for diabetes and obesity are discussed.

Effect of Amine, Carboxyl, or Thiol Functionalization of Mesoporous Silica Particles on Their Efficiency as a Quercetin Delivery System in Simulated Gastrointestinal Conditions

Quercetin (Q) dietary supplements exhibit poor oral bioavailability because of degradation throughout gastrointestinal digestion (GD), which may be overcome using mesoporous silica particles (MSPs) as an oral delivery system (ODS). This study aimed to elucidate the effect of the functionalization of MSPs with amine-(A-MSP), carboxyl-(C-MSP), or thiol-(T-MSP) groups on their efficiency as a quercetin ODS (QODS). The type and degree of functionalization (DF) were used as factors in an experimental design. The Q-loaded F-MSP (F-MSP/Q) was characterized by gas physisorption analysis, loading capacity (LC), and dynamic light scattering and kinetics of Q release at gastric and intestinal pHs. Antioxidant capacity and Q concentration of media containing F-MSP/Q were evaluated after simulated GD. A-MSP showed the highest LC (19.79 ± 2.42%). C-MSP showed the lowest particle size at pH 1.5 or 7.4 (≈200 nm). T-MSP exhibited the maximum Q release at pH 7.4 (11.43%). High DF of A-MSP increased Q retention, regardless of pH. A-MSP preserved antioxidant capacity of Q-released gastric media (58.95 ± 3.34%). Nonetheless, MSP and F-MSP did not protect antioxidant properties of Q released in intestinal conditions. C-MSP and T-MSP showed essential features for cellular uptake and Q release within cells that need to be assessed.

Metformin HCl-loaded transethosomal gel; development, characterization, and antidiabetic potential evaluation in the diabetes-induced rat model

Herein we designed, optimized, and characterized the Metformin Hydrochloride Transethosomes (MTF-TES) and incorporate them into Chitosan gel to develop Metformin Hydrochloride loaded Transethosomal gel (MTF-TES gel) that provides a sustained release, improved transdermal flux and improved antidiabetic response of MTF. Design Expert® software (Ver. 12, Stat-Ease, USA) was applied for the statistical optimization of MTF-TES. The formulation with Mean Particle Size Distribution (MPSD) of 165.4 ± 2.3 nm, Zeta Potential (ZP) of -21.2 ± 1.9 mV, Polydispersity Index (PDI) of 0.169 ± 0.033, and MTF percent Entrapment Efficiency (%EE) of 89.76 ± 4.12 was considered to be optimized. To check the chemical incompatibility among the MTF and other formulation components, Fourier Transform Infrared (FTIR) spectroscopy was performed and demonstrated with no chemical interaction. Surface morphology, uniformity, and segregation were evaluated through Transmission Electron Microscopy (TEM). It was revealed that the nanoparticles were spherical and round in form with intact borders. The fabricated MTF-TES has shown sustained release followed by a more pronounced effect in MTF-TES gel as compared to the plain MTF solution (MTFS) at a pH of 7.4. The MTF-TES has shown enhanced permeation followed by MTF-TES gel as compared to the MTFS at a pH of 7.4. In vivo antidiabetic assay was performed and results have shown improved antidiabetic potential of the MTF-TES gel, in contrast to MTF-gel. Conclusively, MTF-TES is a promising anti-diabetic candidate for transdermal drug delivery that can provide sustained MTF release and enhanced antidiabetic effect.

Hyaluronic acid-graphene oxide quantum dots nanoconjugate as dual purpose drug delivery and therapeutic agent in meta-inflammation

Type 2 diabetes mellitus (T2DM) predominantly considered a metabolic disease is now being considered an inflammatory disease as well due to the involvement of meta-inflammation. Obesity-induced adipose tissue inflammation (ATI) is one of the earliest phenomena in the case of meta-inflammation, leading to the advent of insulin resistance (IR) and T2DM. The key events of ATI are orchestrated by macrophages, which aggravate the inflammatory state in the tissue upon activation, ultimately leading to systemic chronic low-grade inflammation and Non-Alcoholic Steatohepatitis (NASH) through the involvement of proinflammatory cytokines. The CD44 receptor on macrophages is overexpressed in ATI, NASH, and IR. Therefore, we developed a CD44 targeted Hyaluronic Acid functionalized Graphene Oxide Quantum Dots (GOQD-HA) nanocomposite for tissue-specific delivery of metformin. Metformin-loaded GOQD-HA (GOQD-HA-Met) successfully downregulated the expression of proinflammatory cytokines and restored antioxidant status at lower doses than free metformin in both palmitic acid-induced RAW264.7 cells and diet induced obese mice. Our study revealed that the GOQD-HA nanocarrier enhanced the efficacy of Metformin primarily by acting as a therapeutic agent apart from being a drug delivery platform. The therapeutic properties of GOQD-HA stem from both HA and GOQD having anti-inflammatory and antioxidant properties respectively. This study unravels the function of GOQD-HA as a targeted drug delivery option for metformin in meta-inflammation where the nanocarrier itself acts as a therapeutic agent.

Nano-enabled agglomerates and compact: Design aspects of challenges

Nanoscale medicine confers passive and active targeting potential. The development of nanomedicine is however met with processing, handling and administration hurdles. Excessive solid nanoparticle aggregation and caking result in low product yield, poor particle flowability and inefficient drug administration. These are overcome by converting the nanoparticles into a microscale dosage form via agglomeration or compaction techniques. Agglomeration and compaction nonetheless predispose the nanoparticles to risks of losing their nanogeometry, surface composition or chemistry being altered and negating biological performance. This study reviews risk factors faced during agglomeration and compaction that could result in these changes to nanoparticles. The potential risk factors pertain to materials choice in nanoparticle and microscale dosage form development, and their interplay effects with process temperature, physical forces and environmental stresses. To render the physicochemical and biological behaviour of the nanoparticles unaffected by agglomeration or compaction, modes to modulate the interplay effects of material and formulation with processing and environment variables are discussed.

Architecture of Nanoantioxidant Based on Mesoporous Organosilica Trp-Met-PMO with Dipeptide Skeleton

A nanoantioxidant of mesoporous organosilica (Trp-Met-PMO) based on the framework of tryptophan-methionine dipeptide was first designed and constructed by condensation between self-created dipeptide organosilica precursor (Trp-Met-Si) and tetraethyl orthosilicate (TEOS) in alkaline conditions under the template hexadecyl trimethyl ammonium bromide (CTAB). Trp-Met-Si was prepared by the reaction between dipeptide Trp-Met and conventional organosilicon coupling agent isocyanatopropyltriethoxysilane (IPTES) via a multiple-step reaction method. The material Trp-Met-PMO was confirmed by XRD, FT-IR and N₂ adsorption-desorption analysis. The material Trp-Met-5-PMO with low amounts of organosilica precursor remained a mesoporous material with well-ordered 2D hexagonal (P6mm) structure. With increasing amounts of organosilica precursor, a mesoporous structure was still formed, as shown in the material Trp-Met-100-PMO with the highest amounts of organosilica precursor. Moreover, pore size distribution, surface area and porosity of Trp-Met-PMO are regulated with different amounts of organosilica precursor Trp-Met-Si. The antioxidant activity of Trp-Met-PMO was evaluated by ABTS free radical-scavenging assay. The results showed that antioxidant activity was largely enhanced with increasing contents of organosilica precusor Trp-Met-Si in the skeleton. The material Trp-Met-40-PMO exhibited maximum scavenging capacity of ABTS free radicals, the inhibition percent was 5.88%. This study provides a design strategy for nanoantioxidant by immobilizing short peptides within the porous framework of mesoporous material.

Silica-Based Nanomaterials for Diabetes Mellitus Treatment

Diabetes mellitus, a chronic metabolic disease with an alarming global prevalence, is associated with several serious health threats, including cardiovascular diseases. Current diabetes treatments have several limitations and disadvantages, creating the need for new effective formulations to combat this disease and its associated complications. This motivated the development of therapeutic strategies to overcome some of these limitations, such as low therapeutic drug bioavailability or poor compliance of patients with current therapeutic methodologies. Taking advantage of silica nanoparticle characteristics such as tuneable particle and pore size, surface chemistry and biocompatibility, silica-based nanocarriers have been developed with the potential to treat diabetes and regulate blood glucose concentration. This review discusses the main topics in the field, such as oral administration of insulin, glucose-responsive devices and innovative administration routes.

Metformin-Loaded Polymer-Based Microbubbles/Nanoparticles Generated for the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease that is increasingly common all over the world with a high risk of progressive hyperglycemia and high microvascular and macrovascular complications. The currently used drugs in the treatment of T2DM have insufficient glucose control and can carry detrimental side effects. Several drug delivery systems have been investigated to decrease the side effects and frequency of dosage, and also to increase the effect of oral antidiabetic drugs. In recent years, the use of microbubbles in biomedical applications has greatly increased, and research into microactive carrier bubbles continues to generate more and more clinical interest. In this study, various monodisperse polymer nanoparticles at different concentrations were produced by bursting microbubbles generated using a T-junction microfluidic device. Morphological analysis by scanning electron microscopy, molecular interactions between the components by FTIR, drug release by UV spectroscopy, and physical analysis such as surface tension and viscosity measurement were carried out for the particles generated and solutions used. The microbubbles and nanoparticles had a smooth outer surface. When the microbubbles/nanoparticles were compared, it was observed that they were optimized with 0.3 wt % poly(vinyl alcohol) (PVA) solution, 40 kPa pressure, and a 110 μL/min flow rate, thus the diameters of the bubbles and particles were 100 ± 10 μm and 70 ± 5 nm, respectively. Metformin was successfully loaded into the nanoparticles in these optimized concentrations and characteristics, and no drug crystals and clusters were seen on the surface. Metformin was released in a controlled manner at pH 1.2 for 60 min and at pH 7.4 for 240 min. The process and structures generated offer great potential for the treatment of T2DM.

In vitro-in vivo availability of metformin hydrochloride-PLGA nanoparticles in diabetic rats in a periodontal disease experimental model

CONTEXT

Metformin is an important oral anti-hyperglycemic used in diabetes. Polylactic-co-glycolic acid (PLGA) has been widely used due to its reliability in controlling the release of drugs.

OBJECTIVE

This study evaluates the in vitro-in vivo availability of metformin hydrochloride-loaded polylactic-co-glycolic acid.

MATERIAL AND METHODS

In vitro metformin release (Met-free or PLGA + Met-12.5 mg/mL per 360 min) was evaluated using static Franz vertical diffusion cells. The in vivo study was performed with two control groups (validation bioanalytical method) and two experimental groups of diabetic male Wistar rats treated with PLGA + Met 10 mg/kg or Met 100 mg/kg by oral gavage. Diabetes was induced by streptozotocin (40 mg/kg) through the penile vein. Blood samples were collected 0.5, 1, 4, 7, 10, 12, 18, 24, 36, 48 and 72 h and analysed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

RESULTS

PLGA + Met 10 mg/kg was released in the in vitro assay suggesting a parabolic diffusion kinetic model (K -0.0619^-0.5h) with a 100% release profile in 10 h by controlled diffusion. The in vivo assay showed the apparent volume of distribution Vz/F (PLGA + Met 10 mg/kg, 40971.8 mL/kg vs. Met 100 mg/kg, 2174.58 mL/kg) and mean residence time MRTinf (PLGA + Met 10 mg/kg, 37.66 h vs. Met 100 mg/kg, 3.34 h).

DISCUSSION AND CONCLUSIONS

The formulation modifies pharmacokinetics parameters such as apparent distribution volume and mean residence time. The PLGA + Met 10 mg/kg had a slower elimination rate compared to Met 100 mg/kg in diabetic rats in a periodontal disease experimental model.

Bibliometric landscape of the researches on protein corona of nanoparticles

Unclear biological fate hampers the clinical translation of nanoparticles for biomedical uses. In recent years, it is documented that the formation of protein corona upon nanoparticles is a critical factor leading to the ambiguous biological fate. Efforts have been made to explore the protein corona forming behaviors on nanoparticles, and rearrangement of the relevant studies will help to understand the current trend of such a topic. In this work, the publications about protein corona of nanoparticles in Science Citation Index Expanded database of Web of Science from 2007 to 2020 (1417 in total) were analyzed in detail, and the bibliometrics landscape of them was showcased. The basic bibliometrics characteristics were summarized to provide an overall understanding. Citation analysis was performed to scrutinize the peer interests of these papers. The research hotspots in the field were evaluated, based on which some feasible topics for future studies were proposed. In general, the results demonstrated that protein corona of nanoparticles was a prospective research area, and had attracted global research interests. It was believed that this work could comprehensively highlight the bibliometrics landscape, inspire further exploitation on protein corona of nanoparticles, and ultimately promote the clinical translation of nanoparticles.

Targeted combined therapy in 2D and 3D cultured MCF-7 cells using metformin and erlotinib-loaded mesoporous silica magnetic nanoparticles

AIM

This research aims to develop potential therapeutic nanostructures (NSs) encapsulating metformin (MET) and erlotinib (ER) for combinational therapy in breast cancer.

METHODS

The ER and MET, both were loaded on mesoporous silica magnetic nanoparticles conjugated with polyethylene glycol and methotrexate to achieve targeted NSs. The developed NSs were characterised using SEM, DLS, and FTIR. Afterward, MTT, Trypan blue, and DNA extraction assays were operated for biological evaluations in the 2D and 3D MCF-7 cells.

RESULTS

Physicochemical approaches indicated the mean diameter of 69.4 nm ± 9.5 (PDI = 0.64), and neutral charge (2 mv) for the developed NSs. MET and ER-loaded NSs exhibited 62.56% ± 4.41 and 67.73% ± 3.03 drug release amount in pH = 5.4, respectively. MTT assay revealed that ER- and MET-loaded NSs had less metabolic activity (≈ 20%) in comparison with non-targeted NSs.

CONCLUSION

Overall, our combined ER and MET-loaded targeted NSs result in a synergistic inhibitory impact on MCF-7 cells.

Cytotoxicity of mesoporous silica modified by amino and carboxyl groups on vascular endothelial cells

Mesoporous silica is widely used because of its unique and excellent properties, especially it can be used as a drug carrier and gene carrier in the biomedical field. After the mesoporous silica is put into clinical use, it is more likely to be exposed in human body. Therefore, the effect of mesoporous silica on human body cannot be ignored. The injury of vascular endothelial cells is a prerequisite for the occurrence of many cardiovascular diseases. As a drug and gene carrier, mesoporous silica increases its contact with vascular endothelial cells, so its toxic effect on cardiovascular system cannot be ignored. In this study, amino (NH₂ ) and carboxyl (COOH) were modified on mesoporous silica SBA-15 by post-grafting. The results showed that it still maintained the one-dimensional hexagonal mesoporous structure of SBA-15 and had typical mesoporous structure. Then human umbilical vein endothelial cells (HUVECs) were infected with SBA-15, NH₂ -SBA-15, and COOH-SBA-15. The results showed that the functionalized mesoporous silica SBA-15 had cytotoxicity to HUVECs and damaged the cell membrane, but compared with the unmodified mesoporous silica SBA-15 the cytotoxicity of functionalized mesoporous silica SBA-15 was lower and the toxicity of carboxyl modified group was the lowest. By comparing the cell inhibition rate and the expression level of lactate dehydrogenate and reactive oxygen species induced by the three materials, oxidative damage and cell membrane damage may be two mechanisms of cytotoxicity. Mesoporous silica SBA-15 has an effect on cardiovascular system by inducing the high expression of nitric oxide, intercellular adhesive molecule-1 and vascular cell adhesive molecule-1 in HUVECs. In summary, our results show that mesoporous silica is toxic to vascular endothelial cells.

A Recent Update on Drug Delivery Systems for Pain Management

Pain remains a global health challenge affecting approximately 1.5 billion people worldwide. Pain has been an implicit variable in the equation of human life for many centuries considering different types and the magnitude of pain. Therefore, developing an efficacious drug delivery system for pain management remains an open challenge for researchers in the field of medicine. Lack of therapeutic efficacy still persists, despite high throughput studies in the field of pain management. Research scientists have been exploiting different alternatives to curb the adverse side effects of pain medications or attempting a more substantial approach to minimize the prevalence of pain. Various drug delivery systems have been developed such as nanoparticles, microparticles to curb adverse side effects of pain medications or minimize the prevalence of pain. This literature review firstly provides a brief introduction of pain as a sensation and its pharmacological interventions. Second, it highlights the most recent studies in the pharmaceutical field for pain management and serves as a strong base for future developments. Herein, we have classified drug delivery systems based on their sizes such as nano, micro, and macro systems, and for each of the reviewed systems, design, formulation strategies, and drug release performance has been discussed.

The impact of chemical engineering and technological advances on managing diabetes: present and future concepts

Monitoring blood glucose levels for diabetic patients is critical to achieve tight glycaemic control. As none of the current antidiabetic treatments restore lost functional β-cell mass in diabetic patients, insulin injections and the use of insulin pumps are most widely used in the management of glycaemia. The use of advanced and intelligent chemical engineering, together with the incorporation of micro- and nanotechnological-based processes have lately revolutionized diabetic management. The start of this concept goes back to 1974 with the description of an electrode that repeatedly measures the level of blood glucose and triggers insulin release from an infusion pump to enter the blood stream from a small reservoir upon need. Next to the insulin pumps, other drug delivery routes, including nasal, transdermal and buccal, are currently investigated. These processes necessitate competences from chemists, engineers-alike and innovative views of pharmacologists and diabetologists. Engineered micro and nanostructures hold a unique potential when it comes to drug delivery applications required for the treatment of diabetic patients. As the technical aspects of chemistry, biology and informatics on medicine are expanding fast, time has come to step back and to evaluate the impact of technology-driven chemistry on diabetics and how the bridges from research laboratories to market products are established. In this review, the large variety of therapeutic approaches proposed in the last five years for diabetic patients are discussed in an applied context. A survey of the state of the art of closed-loop insulin delivery strategies in response to blood glucose level fluctuation is provided together with insights into the emerging key technologies for diagnosis and drug development. Chemical engineering strategies centered on preserving and regenerating functional pancreatic β-cell mass are evoked in addition as they represent a permanent solution for diabetic patients.

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.

Microfluidic-based synthesized carboxymethyl chitosan nanoparticles containing metformin for diabetes therapy: In vitro and in vivo assessments

This work was aimed to synthesize novel crosslinked carboxymethyl chitosan nanoparticles (CMCS NPs) containing metformin hydrochloride (MET) using microfluidics (MF) and evaluate their performance for diabetes therapy. The field emission-scanning electron microscopy (FE-SEM) images and dynamic light scattering (DLS) results showed that the NPs average size was 77 ± 19 nm with a narrow size distribution. They exhibited a high encapsulation efficiency (∼90 %) and the controlled drug release while crosslinking using CaCl₂. Eventually, the in vivo assessments dedicated an increased body weight up to 7.94 % and a decreased blood glucose level amount of 43.58 % for MF MET-loaded CMCS NPs with respect to the free drug in diabetic rats. Also, the results of histopathological studies revealed the size of the pancreatic islets to be 2.32 μm² and β cells intensity to be 64 cells per islet for the diabetic rats after treating with the MF-based sample. These data were close to those obtained for the healthy rats.

Prolonged proliferation and delayed senescence of the adipose-derived stem cells grown on the electrospun composite nanofiber co-encapsulated with TiO2 nanoparticles and metformin-loaded mesoporous silica nanoparticles

This study was aimed to investigate the effects of the Poly-ε-Caprolactone/Gelatin nanofibers (PCL/GEL NFs) co-encapsulated with TiO₂ nanoparticles (nTiO₂) and metformin-loaded mesoporous silica nanoparticles (MET@MSNs) on prolonging the in vitro expansion of human adipose-derived stem cells (hADSCs) without inducing cellular senescence and aging. FTIR, BET, FE-SEM, and TEM were applied to characterize the fabricated MET@MSNs and electrospun composite NFs. The presence of inorganic particles, nTiO₂ and MSNs, in the scaffolds improved their mechanical properties and led to a more sustained release of MET with almost the lack of the initial burst release from nTiO₂/MET@MSNs-loaded NFs. The enhanced adhesion, metabolic activity, and proliferation rate of the hADSCs grown on nTiO₂/MET@MSNs-loaded NFs were demonstrated via FE-SEM images, MTT test and PicoGreen assay, respectively, over 28 days of culture. Furthermore, the irregular nanofibrillar structures and the impact of sustained release of MET led to a significant upregulation in the mRNA levels of autophagy (Atg-5, Atg-7, Atg-12, and Beclin-1) and stemness (Nanog3, Sox-2, and Oct-4) markers as well as a considerable down-regulation of p16^INK4A senescence marker. Further, the upregulation of hTERT, enhanced activity of telomerase, and increased telomere length were more pronounced in the hADSCs cultured on nTiO₂/MET@MSNs-loaded NFs as compared to other types of NFs. Overall, our findings demonstrated the potential of the fabricated nanocomposite platform for counteracting cellular senescence and achieving sufficient quantities of fresh hADSCs with preserved stemness for various stem cell-based regenerative medicine purposes.

Quantum Dot Nanomedicine Formulations Dramatically Improve Pharmacological Properties and Alter Uptake Pathways of Metformin and Nicotinamide Mononucleotide in Aging Mice

Orally administered Ag₂S quantum dots (QDs) rapidly cross the small intestine and are taken up by the liver. Metformin and nicotinamide mononucleotide (NMN) target metabolic and aging processes within the liver. This study examined the pharmacology and toxicology of QD-based nanomedicines as carriers of metformin and NMN in young and old mice, determining if their therapeutic potency and reduced effects associated with aging could be improved. Pharmacokinetic studies demonstrated that QD-conjugated metformin and NMN have greater bioavailability, with selective accumulation in the liver following oral administration compared to unconjugated formulations. Pharmacodynamic data showed that the QD-conjugated medicines had increased physiological, metabolic, and cellular potency compared to unconjugated formulations (25× metformin; 100× NMN) and highlighted a shift in the peak induction of, and greater metabolic response to, glucose tolerance testing. Two weeks of treatment with low-dose QD-NMN (0.8 mg/kg/day) improved glucose tolerance tests in young (3 months) mice, whereas old (18 and 24 months) mice demonstrated improved fasting and fed insulin levels and insulin resistance. High-dose unconjugated NMN (80 mg/kg/day) demonstrated improvements in young mice but not in old mice. After 100 days of QD (320 μg/kg/day) treatment, there was no evidence of cellular necrosis, fibrosis, inflammation, or accumulation. Ag₂S QD nanomedicines improved the pharmacokinetic and pharmacodynamic properties of metformin and NMN by increasing their therapeutic potency, bypassing classical cellular uptake pathways, and demonstrated efficacy when drug alone was ineffective in aging mice.

Strategies and formulations of freeze-dried tablets for controlled drug delivery

The freeze-drying process has been particularly attractive for preparing tablets for controlled drug release. Although traditional methods, such as granulation or direct compression methods, have been used in various studies to produce tablets with controlled release, freeze-drying processes have been utilized in certain circumstances due to their distinct advantages. However, overall, further development of these strategies, which started with early studies on orally disintegrating tablets, is still necessary. In this review, the incorporation of different formulations into freeze-dried tablets will be discussed. Moreover, the use of excipients, freeze-drying conditions, formulation reconstitution and tablet structure for optimizing the performance of freeze-dried tablets will be reported, including strategies with nanoformulations and natural materials. Generally, this discussion with potential approaches will benefit further development of freeze-dried tablets containing drugs in the pharmaceutical industry.

A ROS-scavenging multifunctional nanoparticle for combinational therapy of diabetic nephropathy

Although synergistic therapy for diabetes mellitus has displayed significant promise for the effective treatment of diabetic nephropathy (DN), developing a simple and effective strategy to construct multifunctional nanoparticles is still a huge challenge. Moreover, the complicated pathological mechanism of DN involves various pathway dysfunctions that limit the effectiveness of a single therapeutic approach. Herein, hollow mesoporous silica nanocomposite (HMSN) particles doped with trace cerium oxide that exhibit renoprotective activity have been designed, which not only have the ability to prevent ROS-associated DN pathogenesis but also have high drug loading capacity. Interestingly, the metformin (MET) loaded multifunctional nanoparticles (MET-HMSN-CeO2) with a special size exhibited significantly increased kidney accumulation over free MET. Moreover, the cyclic conversion between Ce3+ and Ce4+ of mixed-valence ceria in our system provides the possibility for long-term ROS-scavenging activity to achieve the antioxidative effect. Then, we investigated the renoprotective effect of these nanoparticles on the streptozotocin (STZ)-induced renal injury rat model and high-glucose induced NRK-52E cell damage model. As a result, our findings demonstrated that the nanoparticles could alleviate the DN symptoms by mitigating oxidative stress, suppressing cellular apoptosis and protecting renal injury both in vitro and in vivo. The kidney deficits of DN are significantly improved after treatment with MET-HMSN-CeO2. Overall, our studies indicated that the MET-HMSN-CeO2 multifunctional nanoparticles would be a promising therapeutic candidate for DN.

PolyMet-HA nanocomplexs regulates glucose uptake by inhibiting SHIP2 activity

Metformin, the first-line drug to treat type 2 diabetes, inhibits mitochondrial glycerolphosphate dehydrogenase in the liver to suppress gluconeogenesis. The major adverse effects caused by metformin were lactic acidosis and gastrointestinal discomfort. Therefore, there is need to develop a strategy with excellent permeability and appropriate retention effects.In this study, we synthesized a simple and biocompatible PolyMetformin (denoted as PolyMet) through conjugation of PEI_1.8K with dicyandiamide, and then formed PolyMet-hyaluronic acid (HA) nanocomplexs by electrostatic self-assembly of the polycationic PolyMet and polyanionic hyaluronic acid (HA). Similar to metformin, the PolyMet-HA nanocomplexs could reduce the catalytic activity of the recombinant SHIP2 phosphatase domain in vitro. In SHIP2-overexpressing myotubes, PolyMet-HA nanocomplexes ameliorated glucose uptake by downregulating glucose transporter 4 endocytosis. PolyMet-HA nanocomplexes also could restore Akt signaling and protect the podocyte from apoptosis induced by SHIP2 overexpression. In essence, the PolyMet-HA nanocomplexes act similarly to metformin and increase glucose uptake, and maybe have a potential role in the treatment of type 2 diabetes.