Mitochondrial Artificial K+ Channel Construction Using MPTPP@5F8 Nanoparticles for Overcoming Cancer Drug Resistance via Disrupting Cellular Ion Homeostasis.

Mitochondrial potassium ion channels have become a promising target for cancer therapy. However, in malignant tumors, their low expression or inhibitory regulation typically leads to undesired cancer therapy, or even induces drug resistance. Herein, this work develops an in situ mitochondria-targeted artificial K+ channel construction strategy, with the purpose to trigger cancer cell apoptosis by impairing mitochondrial ion homeostasis. Considering the fact that cancer cells have a lower membrane potential than that of normal cells, this strategy can selectively deliver artificial K+ channel molecule 5F8 to the mitochondria of cancer cells, by using a mitochondria-targeting triphenylphosphine (TPP) modified block polymer (MPTPP) as a carrier. More importantly, 5F8 can further specifically form a K+ -selective ion channel through the directional assembly of crown ethers on the mitochondrial membrane, thereby inducing mitochondrial K+ influx and disrupting ions homeostasis. Thanks to this design, mitochondrial dysfunction, including decreased mitochondrial membrane potential, reduced adenosine triphosphate (ATP) synthesis, downregulated antiapoptotic BCL-2 and MCL-1 protein levels, and increased reactive oxygen species (ROS) levels, can further effectively induce the programmed apoptosis of multidrug-resistant cancer cells, no matter in case of pump or nonpump dependent drug resistance. In short, this mitochondria-targeted artificial K+ -selective ion channel construction strategy may be beneficial for potential drug resistance cancer therapy.

Research advances in smart responsive-hydrogel dressings with potential clinical diabetic wound healing properties.

The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem. Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds due to their excellent hydrophilicity, good drug-loading ability and sustained drug release properties. As a typical example, hyaluronic acid dressing (Healoderm) has been demonstrated in clinical trials to improve wound-healing efficiency and healing rates for diabetic foot ulcers. However, the drug release and degradation behavior of clinically-used hydrogel wound dressings cannot be adjusted according to the wound microenvironment. Due to the intricacy of diabetic wounds, antibiotics and other medications are frequently combined with hydrogel dressings in clinical practice, although these medications are easily hindered by the hostile environment. In this case, scientists have created responsive-hydrogel dressings based on the microenvironment features of diabetic wounds (such as high glucose and low pH) or combined with external stimuli (such as light or magnetic field) to achieve controllable drug release, gel degradation, and microenvironment improvements in order to overcome these clinical issues. These responsive-hydrogel dressings are anticipated to play a significant role in diabetic therapeutic wound dressings. Here, we review recent advances on responsive-hydrogel dressings towards diabetic wound healing, with focus on hydrogel structure design, the principle of responsiveness, and the behavior of degradation. Last but not least, the advantages and limitations of these responsive-hydrogels in clinical applications will also be discussed. We hope that this review will contribute to furthering progress on hydrogels as an improved dressing for diabetic wound healing and practical clinical application.

Recent advances in stimuli-responsive polymeric carriers for controllable CRISPR/Cas9 gene editing system delivery.

Non-viral polymeric vectors with good biocompatibility have been recently explored as delivery systems for clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) nucleases. In this review, based on current limitations and critical barriers, we summarize the advantages of stimulus-responsive polymeric delivery vectors (i.e., pH, redox, or enzymes) towards controllable CRISPR/Cas9 genome editing system delivery as well as the advances in using stimulus-responsive CRISPR/Cas9 polymeric carriers towards cancer treatment. Last but not least, the key challenges and promising development strategies of stimulus-responsive polymeric vector designs for CRISPR/Cas9 systems will also be discussed.

Stimuli-Responsive Polymeric Nanovaccines Toward Next-Generation Immunotherapy.

The development of nanovaccines that employ polymeric delivery carriers has garnered substantial interest in therapeutic treatment of cancer and a variety of infectious diseases due to their superior biocompatibility, lower toxicity and reduced immunogenicity. Particularly, stimuli-responsive polymeric nanocarriers show great promise for delivering antigens and adjuvants to targeted immune cells, preventing antigen degradation and clearance, and increasing the uptake of specific antigen-presenting cells, thereby sustaining adaptive immune responses and improving immunotherapy for certain diseases. In this review, the most recent advances in the utilization of stimulus-responsive polymer-based nanovaccines for immunotherapeutic applications are presented. These sophisticated polymeric nanovaccines with diverse functions, aimed at therapeutic administration for disease prevention and immunotherapy, are further classified into several active domains, including pH, temperature, redox, light and ultrasound-sensitive intelligent nanodelivery systems. Finally, the potential strategies for the future design of multifunctional next-generation polymeric nanovaccines by integrating materials science with biological interface are proposed.

Hybrid Polydimethylsiloxane (PDMS) Incorporated Thermogelling System for Effective Liver Cancer Treatment.

For the delivery of anticancer drugs, an injectable in situ hydrogel with thermal responsiveness and prolonged drug release capabilities shows considerable potential. Here, we present a series of thermosensitive in situ hydrogels that serve as drug delivery systems for the treatment of liver cancer. These hydrogels were created by utilizing the polydimethylsiloxane (PDMS) oligomer, polyethylene glycol (PEG) and polypropylene glycol (PPG)'s chemical cross-linking capabilities. Doxorubicin (DOX) was encapsulated in a hydrogel with a hydrophobic core and hydrophilic shell to enhance DOX solubility. Studies into the behavior of in situ produced hydrogels at the microscopic and macroscopic levels revealed that the copolymer solution exhibits a progressive shift from sol to gel as the temperature rises. The hydrogels' chemical composition, thermal properties, rheological characteristics, gelation period, and DOX release behavior were all reported. Subcutaneous injection in mice was used to confirm the injectability. Through the in vitro release of DOX in a PBS solution that mimics the tumor microenvironment, the hydrogel's sustained drug release behavior was confirmed. Additionally, using human hepatocellular hepatoma, the anticancer efficacy of thermogel (DEP-2@DOX) was assessed (HepG2). The carrier polymer material DEP-2 was tested for cytotoxicity using HepG2 cells and its excellent cytocompatibility was confirmed. In conclusion, these thermally responsive injectable hydrogels are prominent potential candidates as drug delivery vehicles for the treatment of hepatocellular carcinoma.

Recent advances in mechanical force-responsive drug delivery systems.

Mechanical force responsive drug delivery systems (in terms of mechanical force induced chemical bond breakage or physical structure destabilization) have been recently explored to exhibit a controllable pharmaceutical release behaviour at a molecular level. In comparison with chemical or biological stimulus triggers, mechanical force is not only an external but also an internal stimulus which is closely related to the physiological status of patients. However, although this mechanical force stimulus might be one of the most promising and feasible sources to achieve on-demand pharmaceutical release, current research in this field is still limited. Hence, this tutorial review aims to comprehensively evaluate the recent advances in mechanical force-responsive drug delivery systems based on different types of mechanical force, in terms of direct stimulation by compressive, tensile, and shear force, or indirect/remote stimulation by ultrasound and a magnetic field. Furthermore, the exciting developments and current challenges in this field will also be discussed to provide a blueprint for potential clinical translational research of mechanical force-responsive drug delivery systems.

The Translational Application of Hydrogel for Organoid Technology: Challenges and Future Perspectives.

Human organoids mimic the physiology and tissue architecture of organs and are of great significance for promoting the study of human diseases. Traditionally, organoid cultures rely predominantly on animal or tumor-derived extracellular matrix (ECM), resulting in poor reproducibility. This limits their utility in for large-scale drug screening and application for regenerative medicine. Recently, synthetic polymeric hydrogels, with high biocompatibility and biodegradability, stability, uniformity of compositions, and high throughput properties, have emerged as potential materials for achieving 3D architectures for organoid cultures. Compared to conventional animal or tumor-derived organoids, these newly engineered hydrogel-based organoids more closely resemble human organs, as they are able to mimic native structural and functional properties observed in-situ. In this review, recent developments in hydrogel-based organoid culture will be summarized, emergent hydrogel technology will be highlighted, and future challenges in applying them to organoid culture will be discussed.

Multifunctionalized Micelles Facilitate Intracellular Doxorubicin Delivery for Reversing Multidrug Resistance of Breast Cancer.

Intracellular doxorubicin (DOX) pumping out of cells through the P-glycoprotein (P-gp) transporter leads to the reduction of intracellular DOX levels and induces multidrug resistance (MDR). A hyaluronic acid-deoxycholic acid-histidine and Pluronic F127 (PF127) mixed micellar system, named HA-DOCA-His-PF micelles, functionalized with active targeted endocytosis mediated via CD44 receptor, intracellular triggered DOX release under endosome-pH, and combined with PF127-mediated P-gp efflux inhibition was developed for sufficient intracellular DOX delivery and MDR reversion. The DOX/HA-DOCA-His-PF drug-loaded micelles displayed endosomal pH-mediated self-assembly/disassembly characteristics, triggered DOX release under an endosomal (pH 5.5) environment, and demonstrated enhanced cytotoxicity and superior MDR reversion performance against drug-resistant MCF-7/Adr tumor cells. Importantly, superior antitumor activity of DOX/HA-DOCA-His-PF micelles was presented on the growth inhibition of MCF-7/Adr tumor cells, by further inhibiting the P-gp activity on intracellular DOX efflux through the depletion of intracellular adenosine triphosphate content. This multifunctional micellar system could be facilitated by the intracellular DOX delivery for reversing MDR of breast cancer.

Ion-pair formation combined with a penetration enhancer as a dual strategy to improve the transdermal delivery of meloxicam.

The aim of the study was to develop a novel drug-in-adhesive patch for transdermal delivery of meloxicam (MLX). The formulation involved a strategy to combine a chemical enhancer with an ion-pair agent. Diethylamine (DETA) was selected as the counter ion to form the ion-pair agent MLX-DETA. MLX-DETA was characterized by nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). The ion-pair lifetime (T life) of MLX-DETA was 164.1 µs. The water solubility of MLX-DETA was increased nearly 9.3-fold, compared with that of MLX. Oleic acid (OA) was selected as the chemical enhancer, and the optimized formulation consisted of 5% (w/w) MLX-DETA, 5% (w/w) oleic acid, and DURO-TAK® 87-4098 adhesive as the pressure-sensitive adhesive matrix. The permeation study in vitro showed that both the counter ion and chemical enhancer were effective in improving the skin permeation of MLX. Tissue distribution studies demonstrated that higher accumulation of MLX following application of the MLX-DETA patch to the skin could be obtained in rats compared with the MLX-patch group. In conclusion, to increase the skin absorption and obtain a sustained release for the transdermal delivery of MLX, preparation of a drug-in-adhesive patch by combining an ion pair (MLX-DETA) with a permeation enhancer (OA) is a suitable strategy.

In-vitro and in-vivo study of amorphous spironolactone prepared by adsorption method using supercritical CO2.

OBJECTIVE: The aim of this study was to improve the oral bioavailability of spironolactone (SP). METHOD: SP was adsorbed on the fumed silica using supercritical CO2 (scCO2) technology and further compressed into tablets. The morphology was observed by scanning electron microscopy (SEM), and the crystalline form was investigated by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The dissolution test was performed in water, 0.1 M HCl solution, pH 4.5 acetate buffers and pH 6.8 phosphate buffers using the paddle method. The pharmacokinetics was undertaken in six dogs in a crossover fashion. RESULTS: SP was successfully prepared into tablets and presented in amorphous state. SP-silica scCO2 tablets displayed higher dissolution profiles than SP-silica physical mixtures tablets in different media. The AUC0-t and Cmax of SP-silica supercritical CO2 was 1.61- and 1.52-fold greater than those of SP-silica physical mixtures (p < 0.05), respectively. CONCLUSION: It is a promising method in improving dissolution and bioavailability by adsorbing SP, a poorly soluble drug, on the fumed silica using rapid expansion of supercritical solutions.

Simultaneous determination of oxiracetam and its degraded substance in rat plasma by HPLC-MS/MS and its application to pharmacokinetic study after a single high-dose intravenous administration.

A simple, rapid and sensitive reversed-phase ultra-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated for the simultaneous quantitative determination of oxiracetam and its degraded substance 4-hydroxy-2-oxo-1-pyrrolidine acetic acid (HOPAA) in rat plasma. After plasma samples were deproteinized with acetonitrile, the post-treatment samples were analyzed on a C18 column interfaced with a triple quadrupole tandem mass spectrometer in the positive electrospray ionization mode at a flow rate of 0.35ml/min. Piracetam was used as internal standard (IS). Multiple selected reaction monitoring was performed using the transitions m/z 159.00→141.94, 159.95→113.98 and 142.98→125.97 to quantify oxiracetam, HOPAA and IS, respectively. This method was validated over the concentration range of 25-2250µg/ml for oxiracetam (r(2)≥0.99) and 0.5-250µg/ml (r(2)≥0.99) for HOPAA. Intra-run and inter-run precision values of oxiracetam and HOPAA were less than 15% and accuracy was within 85-115% at all quality control levels. The average extraction recovery was 93.9% for oxiracetam and 95.6% for HOPAA, respectively. In conclusion, a simple, sensitive and specific HPLC-MS/MS method was successfully applied to the pharmacokinetic study in rats after an intravenous administration at a high dose of 2g/kg.

Development of a supercritical fluid chromatography-tandem mass spectrometry method for the determination of lacidipine in beagle dog plasma and its application to a bioavailability study.

A simple, novel, rapid and sensitive supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) method was developed and validated for the determination of lacidipine in beagle dog plasma with nimodipine as internal standard. The method involved a simple liquid-liquid extraction method with tert-butyl methyl ether. The analytes were analyzed on an Acquity UPC(2) with a HSS C18 SB column (3mm×100mm, 1.8µm) set at 50°C. The mobile phase was carbon dioxide (≥99.99%) and methanol (92:8, v/v) at a flow rate of 2ml/min, the compensation solvent was methanol with 2% formic acid at a flow rate of 0.2ml/min and a total analysis time of 1.5min for each sample. The multiple reaction-monitoring mode was used for quantification of ion transitions at m/z 473.32→354.10 and 419.00→343.10 for lacidipine and internal standard, respectively. The linearity range of proposed method was 0.10-100ng/ml) (r(2)≥0.9990). The intra- and inter-day precision values were less than 15% and accuracy was from -0.83% to 3.27% at all quality control levels. The proposed method was successfully applied to a pharmacokinetic study of lacidipine in beagle dogs.