In this research, a novel MgSiO3 fiber membrane (MSFM) loaded with indocyanine green (ICG) and doxorubicin (DOX) was prepared. Because of MgSiO3\'s unique lamellar structure composed of a silicon-oxygen tetrahedron, magnesium ion (Mg2+) moves easily and can be further replaced with other cations. Therefore, because of the positively charged functional group of ICG, MSFM has a rather high drug loading for ICG. In addition, there is electrostatic attraction between DOX (a cationic drug) and ICG (an anionic drug). Hence, after loading ICG, more DOX can be adsorbed into MSFM because of electrostatic interaction. The ICG endows the MSFM outstanding photothermal therapy (PTT) performance, and DOX as a chemotherapeutic drug can restrain tumor growth. On the one hand, H+ exchanged with the positively charged DOX based on the MgSiO3 special lamellar structure. On the other hand, the thermal effect could break the electrostatic interaction between ICG and DOX. Based on the above two points, both tumor acidic microenvironment and photothermal effect can trigger DOX release. What\'s more, in vitro and in vivo antiosteosarcoma therapy evaluations displayed a superior synergetic PTT-chemotherapy anticancer treatment and excellent biocompatibility of DOX&ICG-MSFM. Finally, the MSFM was proven to greatly promote cell proliferation, differentiation, and bone regeneration performance in vitro and in vivo. Therefore, MSFM provides a creative perspective in the design of multifunctional scaffolds and shows promising applications in controlled drug delivery, antitumor performance, and osteogenesis.

Controlled drug delivery systems offer numerous advantages. This research evaluates Opuntia leaf mucilage grafted with polyacrylamide (OPM-g-PAM) as a promising controlled-release polymer. PAM chains were grafted onto the backbone of OPM using a microwave-assisted method. Optimization of the best grade was based on % grafting efficiency and intrinsic viscosity, followed by extensive physical and analytical characterizations. Analytical characterizations revealed semicrystalline nature of the biomaterial. SEM and AFM observations revealed rough and porous surfaces, indicating effective grafting. Swelling behavior showed maximum sensitivity at pH 7, with reduced swelling at higher sodium chloride concentrations. A comparative study of % drug release of Rosuvastatin over 24 h showed that the optimized grade controlled drug release effectively, achieving 78.5 % release compared to 98.8 % for GF-3. The release data fitted the Korsmeyer-Peppas model, with an \"n\" value of 0.8334, indicating non-Fickian (anomalous) diffusion. Bacterial biodegradability studies confirmed the high biodegradability of the graft copolymer. In vitro acute toxicity tests showed no toxicity, as confirmed by histopathological studies of heart, liver, and kidney. Overall, the results indicate that OPM-g-PAM is a highly promising material for use in drug delivery systems, demonstrating potential as a novel controlled-release polymer.

Herein, poly(N-(4-aminophenyl)methacrylamide)-carbon nano-onions [abbreviated as PAPMA-CNOs (f-CNOs)] integrated gallic acid cross-linked zein composite fibers (ZG/f-CNOs) were developed for the removal/recovery of phosphate from wastewater along with controlled drug delivery and intrinsic antibacterial characteristics. The composite fibers were produced by Forcespinning followed by a heat-pressure technique. The obtained ZG/f-CNOs composite fibers presented several favorable characteristics of nanoadsorbents and drug carriers. The composite fibers exhibited excellent adsorption capabilities for phosphate ions. The adsorption assessment demonstrated that composite fibers process highly selective sequestration of phosphate ions from polluted water, even in the presence of competing anions. The ZG/f-CNOs composite fibers presented a maximum phosphate adsorption capacity (qmax) of 2500 mg/g at pH 7.0. This represents the most efficient phosphate adsorption system among all of the reported nanocomposites to date. The isotherm studies and adsorption kinetics of the adsorbent showed that the adsorption experiments followed the pseudo-second-order and Langmuir isotherm model (R2 = 0.9999). After 13 adsorption/desorption cycles, the adsorbent could still maintain its adsorption efficiency of 96-98% at pH 7.0 while maintaining stability under thermal and chemical conditions. The results mark significant progress in the design of composite fibers for removing phosphates from wastewater, potentially aiding in alleviating eutrophication effects. Owing to the f-CNOs incorporation, ZG/f-CNOs composite fibers exhibited controlled drug delivery. An antibiotic azithromycin drug-encapsulated composite fibers presented a pH-mediated drug release in a controlled manner over 18 days. Furthermore, the composite fibers displayed excellent antibacterial efficiency against Gram-positive and Gram-negative bacteria without causing resistance. In addition, zein composite fibers showed augmented mechanical properties due to the presence of f-CNOs within the zein matrix. Nonetheless, the robust zein composite fibers with inherent stimuli-responsive drug delivery, antibacterial properties, and phosphate adsorption properties can be considered promising multifunctional composites for biomedical applications and environmental remediation.

At present, the efficacy and safety of many sparingly-soluble tyrosine kinase inhibitors (TKIs) delivered by the prevalent oral dosage forms are compromised by excessive fluctuations in the drug concentration in blood. To mitigate this limitation, in this four-part study gastroretentive fibrous dosage forms that deliver drug into the gastric fluid (and into the blood) at a controlled rate for prolonged time are presented. The dosage form comprises a cross-ply structure of expandable, water-absorbing, high-molecular-weight hydroxypropyl methylcellulose (HPMC)-based fibers coated with a strengthening, enteric excipient. The intervening spaces between the coated fibers are solid annuli of drug particles, and low-molecular-weight HPMC and enteric excipients. The central regions of the annuli are open channels. In this part, models are developed for dosage form expansion, post-expansion mechanical strength, and drug release. The models suggest that upon immersing in a dissolution fluid, the fluid percolates the open channels, diffuses into the annuli and the coated fibers, and the dosage form expands. The expansion rate is inversely proportional, and the post-expansion mechanical strength proportional to the thickness of the strengthening coating. Drug particles are released from the annuli as the surrounding excipient dissolves. The drug release rate is proportional to the concentration of low-molecular-weight HPMC at the annulus/dissolution fluid interface. The dosage forms can be readily designed for expansion in a few hours, formation of a high-strength viscoelastic mass, and drug release at a constant rate over a day.

In Part 1, we have introduced expandable gastroretentive fibrous dosage forms for prolonged delivery of sparingly-soluble tyrosine kinase inhibitors. The expansion rate, post-expansion mechanical strength, and drug release rate were modeled for a dosage form containing 200 mg nilotinib. In the present part, the dosage form was prepared and tested in vitro to validate the models. Upon immersing in a dissolution fluid, the fibrous dosage form expanded at a constant rate to a normalized radial expansion of 0.5 by 4 h, and then formed an expanded viscoelastic mass of high strength. The drug was released at a constant rate over a day. For comparison, a particle-filled gelatin capsule with the same amount of nilotinib disintegrated almost immediately, and released eighty percent of the drug content in just 10 min. The experimental data validate the theoretical models of Part 1 reasonably.

In this final part, the models of drug concentration in blood developed in Part 3 are validated on dogs. Both slow-release gastroretentive fibrous and immediate-release particulate dosage forms containing 200 mg nilotinib were tested. After administering, the fibrous dosage form expanded linearly with time in the stomach, to about 1.5 times the initial radius by 4 h. The expanded dosage form fractured after 10 h, and then passed into the intestines. The drug concentration in blood exhibited a broad peak with a maximum of 0.51 μg/ml and a width at half-height of 10.2 h. By contrast, after administering the immediate-release capsule the drug concentration in blood exhibited a sharp peak with a maximum of 0.68 μg/ml and a width at half-height of just 3.6 h. The experimental data validate the theoretical models reasonably. The gastroretentive fibrous dosage forms designed in this study enable a steady drug concentration in blood for increasing the efficacy and mitigating side effects of drug therapies.

In this part, drug concentration in blood after ingesting slow-release gastroretentive fibrous dosage forms and immediate-release particulate forms is modeled. The tyrosine kinase inhibitor nilotinib, which is slightly soluble in low-pH gastric fluid but practically insoluble in pH-neutral intestinal fluid is used as drug. The models suggest that upon ingestion, the fibrous dosage form expands, is retained in the stomach for prolonged time, and releases drug into the gastric fluid at a constant rate. The released drug molecules flow into the duodenum with the gastric fluid, and are absorbed by the blood. The drug is eliminated from the blood by the liver at a rate proportional to its concentration. Eventually, the elimination and absorption rates will be equal, and the drug concentration in blood plateaus out. After the gastric residence time drug absorption stops, and the drug concentration in blood drops to zero. By contrast, after administering an immediate-release particulate dosage form the drug particles are swept out of the stomach rapidly, and drug absorption stops much earlier. The drug concentration in blood rises and falls without attaining steady state. The gastroretentive fibrous dosage forms enable a constant drug concentration in blood for drugs that are insoluble in intestinal fluids.

Bacteria-infected wounds healing has been greatly hindered by antibiotic resistance and persistent inflammation. It is crucial to develop multifunctional nanocomposites that possess effective antibacterial properties and can simultaneously accelerate the wound healing process to overcome the above challenges. Herein, we prepared a yolk-shell structured Ag nanowires (NWs)@amorphous hollow ZIF-67 by etching ZIF-67 onto the Ag NWs for infected wound healing for the first time. The etched hollow structure of amorphous ZIF-67 in the nanocomposite makes it a promising platform for loading healing-promoting drugs. We extensively studied the antibacterial and healing-promoting properties of the curcumin (CCM)-loaded nanocomposite (Ag NWs@C-HZ67). Ag NWs, being noble metal materials with plasmonic effects, can absorb a broad range of natural light and convert it to thermal energy. This photothermal conversion further improves the release of antibacterial components and wound healing drugs when exposed to light. During the healing process of an infected wound, Ag and Co ions were released from Ag NWs@C-HZ67 upon direct contact with the wound exudate and under the influence of light irradiation. Simultaneously, the loaded CCM leaked out to repair the infected wound. The minimum inhibitory concentrations of the Ag NWs@C-HZ67 groups against Escherichia coli and Staphylococcus aureus bacteria decreased to 3 and 3 μg ml-1 when exposed to white light. Furthermore, an in vivo assessment of infected wound healing demonstrated that combining Ag NWs@C-HZ67 with light significantly accelerated the wound healing process, achieving 70% healing by the 6th day and almost complete healing by the 8th day. This advanced nanocomposite, consisting of components that possess antibacterial and growth-promoting properties, offers a safe, effective and clinically-translatable solution for accelerating the healing process of infected wounds.

This study introduces a pH-responsive hydrogel developed from Delonix regia and mucin co-poly(acrylate) through free radical polymerization to enhance controlled drug delivery systems. Characterization using FTIR, DSC, TGA, SEM, PXRD, and EDX spectroscopy detailed the hydrogel\'s amorphous and crystalline structures, thermal stability, surface characteristics, and elemental composition. Tested at a pH of 7.4-mimicking intestinal conditions-the hydrogel demonstrated significant swelling, indicating its capability for targeted drug release. With Metformin HCl as a model drug, the hydrogel exhibited a promising sustained release profile, underscoring its potential for oral administration. Safety and biocompatibility were assessed through acute oral toxicity studies in albino rabbits, encompassing biochemical, hematological, and histopathological evaluations. X-ray imaging confirmed the hydrogel\'s navigability through the gastrointestinal tract, affirming its application in drug delivery. By potentially mitigating gastrointestinal side effects, enhancing patient compliance, and improving therapeutic efficacy, this Delonix regia/mucin co-poly(acrylate) hydrogel represents a step in pharmaceutical sciences, exploring innovative materials and methodologies for drug delivery.

Skin injury is one of the most prevalent lesions in humans, and many such wounds, including deep burns and chronic skin wounds, are notoriously difficult to heal. It has been established by medical practitioners that current wound therapies are not perfectly effective and are far from satisfactory. Meanwhile, nanotechnologies have made it possible to develop pharmaceutical formulations that can elevate the effectiveness of conventional pharmacotherapies to entirely new heights. Most nanostructured biomaterials used to treat wounds, including those that have helped establish this fascinating subject, have been polymeric. The bibliographic analysis presented here shows a steady growth in the research output of studies on the use of polymeric nanoparticles in wound healing therapies. This article provides an overview of polymeric nanoparticles for the treatment of wounds with an emphasis on different chemistries and polymer-drug combinations that have been proven the most effective. The wound age, pathophysiology, wound healing treatments of the present and past, as well as the physicochemical nature and methods for the synthesis of polymeric nanoparticles, are all covered in the opening parts of the review. The existing polymeric nano-drug delivery systems with the greatest promise for wound healing and skin regeneration are subsequently addressed and their potentials summarized.