A geometric pore adsorption model for predicting the drug loading capacity of insoluble drugs in mesoporous carbon

A universal powder-laden crosslinked chitosan microneedle patch for high-dose controllable drug delivery

In this study, we constructed a novel powder-laden core-shell crosslinked chitosan microneedle patch for high-dose and controllable delivery of various drugs, including both macromolecular biological drugs and small-molecule chemical drugs. Direct loading of drug powders greatly improved drug loading capacity and minimized degradation. The results of the in vitro drug release study suggested that the release behaviors of the most tested drugs (both macromolecular drugs and small-molecule drugs) can be tuned by adjusting the crosslink density of the microneedle shell to achieve either rapid or sustained release of the loaded drug. The in vivo hypoglycemic efficacy test in streptozotocin-induced diabetic mice further proved that the onset and duration of the insulin-laden patch can be customized by adjusting the crosslink density. Furthermore, a combination of microneedle patches with different crosslink densities not only rapidly reduced blood glucose levels to normoglycemic levels (within 1 h) but also maintained normoglycemia for up to 36 h. The insulin loaded in the patch also showed good stability during storage at 40 °C for 6 months. Our results suggest that this powder-laden patch represents a strong candidate for addressing the multiple challenges in the preparation and application of polymeric microneedles and shows promise in clinical applications.

H2O2 generation enhancement by ultrasonic nebulisation with a zinc layer for spray disinfection

With the outbreak of COVID-19, microbial pollution has gained increasing attention as a threat to human health. Consequently, many research efforts are being devoted to the development of efficient disinfection methods. In this context, hydrogen peroxide (H₂O₂) stands out as a green and broad-spectrum disinfectant, which can be produced and sprayed in the air directly by cavitation in ultrasonic nebulisation. However, the yield of H₂O₂ obtained by ultrasonic nebulisation is too low to satisfy the requirements for disinfection by spraying and needs to be improved to achieve efficient disinfection of the air and objects. Herein, we report the introduction of a zinc layer into an ultrasonic nebuliser to improve the production of H₂O₂ and generate additional Zn²⁺ by self-corrosion, achieving good disinfecting performance. Specifically, a zinc layer was assembled on the oscillator plate of a commercial ultrasonic nebuliser, resulting in a 21-fold increase in the yield of H₂O₂ and the production of 4.75 μg/mL Zn²⁺ in the spraying droplets. When the generated water mist was used to treat a bottle polluted with Escherichia coli for 30 min, the sterilisation rate reached 93.53%. This ultrasonic nebulisation using a functional zinc layer successfully enhanced the production of H₂O₂ while generating Zn²⁺, providing a platform for the development of new methodologies of spray disinfection.

An electrochemical enzymatic nanoreactor based on dendritic mesoporous silica nanoparticles for living cell H2O2 detection

The selective and quantitative detection of cellular H2O2 is essential for understanding its roles in physiology and pathology. A new electrochemical H2O2 biosensor, fabricated by immobilizing horseradish peroxidase onto dendritic mesoporous silica nanoparticles (HRP/DMSNs), is employed for living cell H2O2 detection. Taking advantage of the large pore volume and highly accessible internal surface areas of DMSNs, HRP/DMSNs display higher enzymatic loading, better stability and bioactivity in comparison with HRP on nonporous silica nanoparticles (NSNs). Therefore, a HRP/DMSN modified GCE (HRP/DMSNs/GCE) shows attractive electrochemical performance for sensitive and selective detection of H2O2 in 0.1 M pH 7.0 PBS, with a low Kappm value of 11.48 μM and a low detection limit of 0.11 μM. In addition, HRP/DMSNs/GCE is successfully applied to detect H2O2 released from a PC12 cell triggered by ascorbic acid (AA). The detected H2O2 amount is close to the reported values. The developed biosensor has potential in the dynamic detection of the flux of H2O2 from living cells for further evaluation of oxidative stress in cells.

Polyphenol oxidase/gold nanoparticles/mesoporous carbon-modified electrode as an electrochemical sensing platform for rutin in dark teas

In the communication, by virtue of the excellent conductivity and great surface area of mesoporous carbon (FDU-15), the enhanced conductivity of Au NPs, and the good electrochemical response of polyphenol oxidase (PPO) to rutin, a PPO/AuNPs/FDU-15-modified electrode was used as a candidate for the determination of rutin in dark teas with satisfactory results.

By virtue of great surface area of mesoporous carbon, enhanced conductivity of AuNPs, and good electrochemical response of polyphenol oxidase to rutin, a PPO/AuNPs/FDU-15-modified electrode was used for the determination of rutin in dark teas.

A carbon based drug delivery system derived from a one-dimensional coordination polymer, doxorubicin loading and redox-responsive release

A redox-responsive drug delivery system has been fabricated through the modification of –S–S– bonds on coordination polymer derived mesoporous carbon nanoparticles with Ag as a “gatekeeper”.

An Intelligent and Tumor-Responsive Fe2+ Donor and Fe2+-Dependent Drugs Cotransport System

Fe²⁺ plays an essential role for artemisinin (ART)-based drugs in anticancer therapy. As a result, it is important to realize these two agents' cotransport for improving antitumor efficacy. We utilized a kind of alternating magnetic field (AMF) and tumor-responsive material-mesoporous Fe₃O₄ (mFe₃O₄)-to encapsulate ART. After that, the outer surface of mFe₃O₄ was capped with multifunctional hyaluronic acid (HA), which was used not only as a smart gatekeeper but also as a tumor targeting moiety. In vitro and in vivo studies proved that ART can be encapsulated in HA-mFe₃O₄ and protected by HA coating which could effectively avoid premature release during in vivo circulation. HA-mFe₃O₄/ART could be taken up by MCF-7 tumor cells via CD44 receptor-mediated endocytosis and locate at acidic lysosome. Subsequently, "HA gate" could be degraded by acidity and hyaluronidase. Then this system synchronously released Fe²⁺ and ART at the same site. Fe²⁺ can nonenzymatically convert ART to ROS for killing cancer cells. Under AMF irradiation, HA-mFe₃O₄ could not only effectively convert electromagnetic wave into heat for tumor thermal therapy but also generate high levels of reactive oxygen species (ROS) for tumor dynamic therapy. These results demonstrated that the antitumor efficacy of HA-mFe₃O₄/ART in vivo significantly enhanced 3.7 times compared with free ART. Combining with AMF, it further improved 3.9 times (V/V0 of 0.11), suggesting the successful combined application of HA-mFe₃O₄/ART and AMF for tumor treatment. It is believed that HA-mFe₃O₄/ART is a promising system for Fe²⁺-dependent drugs to improve their therapeutic effect.

Novel Nanostructured Solid Materials for Modulating Oral Drug Delivery from Solid-State Lipid-Based Drug Delivery Systems

Lipid-based drug delivery systems (LBDDS) have gained significant attention in recent times, owing to their ability to overcome the challenges limiting the oral delivery of poorly water-soluble drugs. Despite the successful commercialization of several LBDDS products over the years, a large discrepancy exists between the number of poorly water-soluble drugs displaying suboptimal in vivo performances and the application of LBDDS to mitigate their various delivery challenges. Conventional LBDDS, including lipid solutions and suspensions, emulsions, and self-emulsifying formulations, suffer from various drawbacks limiting their widespread use and commercialization. Accordingly, solid-state LBDDS, fabricated by adsorbing LBDDS onto a chemically inert solid carrier material, have attracted substantial interest as a viable means of stabilizing LBDDS whilst eliminating some of the various limitations. This review describes the impact of solid carrier choice on LBDDS performance and highlights the importance of appropriate solid carrier material selection when designing hybrid solid-state LBDDS. Specifically, emphasis is placed on discussing the ability of the specific solid carrier to modulate drug release, control lipase action and lipid digestion, and enhance biopharmaceutical performance above the original liquid-state LBDDS. To encourage the interested reader to consider their solid carrier choice on a higher level, various novel materials with the potential for future use as solid carriers for LBDDS are described. This review is highly significant in guiding future research directions in the solid-state LBDDS field and fostering the translation of these delivery systems to the pharmaceutical marketplace.