Polymer mechanochemistry in drug delivery: From controlled release to precise activation

Mechanical properties of carriers based on natural polymers: Polysaccharides, proteins, and lipids as wall materials

Traditional synthetic polymer carriers are restricted due to microplastic pollution, whereas, natural polymer materials have gained widespread use as wall materials for carriers due to their biodegradability, availability, ease of modification, and biocompatibility. The mechanical properties of carriers are particularly crucial for formulation design, storage stability, and practical performance. However, there is currently a lack of reviews on the mechanical properties of natural polymer-based carriers (NPC). This paper delves into the mechanical properties of NPC from five aspects: First, natural polymer wall materials are classified into polysaccharide-based, protein-based, lipid-based, and composite materials, focusing on polysaccharide-dominated systems, and the mechanical properties of NPC constructed from materials of different origins are summarized. Second, various preparation techniques for NPC are introduced, summarizing the mechanical properties of carriers constructed by each method. The paper then examines regulation strategies of the mechanical properties of NPC, including modification techniques, encapsulated substances, morphology, and particle size. Next, methods for characterizing mechanical properties of NPC are introduced. Finally, there is a summary of the progress of NPCs with different mechanical properties in fields, highlighting the challenges faced and proposing future research directions. This review links mechanical optimization to performance, bridging research and applications with eco-friendly NPC strategies.

Advanced oral drug delivery systems for gastrointestinal targeted delivery: the design principles and foundations

Oral administration has long been considered the most convenient method of drug delivery, requiring minimal expertise and invasiveness. Unlike injections, it avoids discomfort, wound infections, and complications, leading to higher patient compliance. However, the effectiveness of oral delivery is often hindered by the harsh biological barriers of the gastrointestinal tract, which limit the bioaccessibility and bioavailability of drugs. The development of oral drug delivery systems (ODDSs) represents a critical area for the advancement of pharmacotherapy. This review highlights the characteristics and precise targeting mechanisms of ODDSs. It first examines the unique properties of each gastrointestinal compartment, including the stomach, small intestine, intestinal mucus, intestinal epithelial barrier, and colon. Based on these features, it outlines the targeting strategies and design principles for ODDSs aimed at overcoming gastrointestinal barriers to enhance disease treatment. Lastly, the review discusses the challenges and potential future directions for ODDS development, emphasizing their importance for advancing drug delivery technologies and accelerating their future growth.

Current developments in diverse biomaterial formulations for ultrasound-mediated drug delivery

In this review, we focus on advances in drug delivery systems (DDSs) pertaining to modern therapeutics, with a particular emphasis on the role of ultrasound (US)-mediated drug delivery (UMDD). We highlight the need for advanced systems in response to several challenges, such as the diversity of pharmacological agents and individual patient variations, over traditional methodologies. We detail the mechanisms of UMDD (thermal and mechanical), and discuss various material formulations suitable for UMDD. We also discuss new perspectives on the potential of US to innovate drug delivery methodologies and improve patient outcomes to emphasize the importance of development to enhance treatment effectiveness.

Development of MhOR1 as a chemogenetic tool for odorant-mediated regulation of insulin release

Our study presents MhOR1, an odorant-responsive chemogenetic tool that facilitates calcium influx upon odorant activation. We optimized its membrane expression and demonstrated its ability to regulate insulin release in pancreatic β cells. Our results suggest that MhOR1 holds potential for gene regulation and therapeutic applications through odorant-triggered cellular activities.

Mechanochemical Release of 9,10-Diphenylanthracene via Flex-Activation of Its 1,4-Diels-Alder Adduct

Flex-activated mechanophores capable of releasing small molecules utilize bond bending to facilitate their mechanochemical activation without compromising the overall macromolecular architecture, which have great potential in various applications. However, the development of such mechanophores remains underexplored. Here we report a novel flex-activated mechanophore based on the 1,4-Diels-Alder (DA) adduct of 9,10-diphenylanthracene (DPA) with acetylenedicarboxylate (ADC). Compression of the mechanophore-crosslinked polymer networks mechanochemically activates the weakly fluorescent DPA-ADC mechanophores to undergo a retro-DA reaction in accompany with the release of highly fluorescent DPA molecules (quantum yield close to unity), as confirmed by fluorescence spectroscopy and gas chromatography-mass spectrometry (GC-MS) analysis. As a new member of the small family of flex-activated mechanophores, this fluorogenic DPA-ADC mechanophore possesses promising applications in stress sensing and damage detection.

Cancer theragnostics: closing the loop for advanced personalized cancer treatment through the platform integration of therapeutics and diagnostics

Cancer continues to be one of the leading causes of death worldwide, and conventional cancer therapies such as chemotherapy, radiation therapy, and surgery have limitations. RNA therapy and cancer vaccines hold considerable promise as an alternative to conventional therapies for their ability to enable personalized therapy with improved efficacy and reduced side effects. The principal approach of cancer vaccines is to induce a specific immune response against cancer cells. However, a major challenge in cancer immunotherapy is to predict which patients will respond to treatment and to monitor the efficacy of the vaccine during treatment. Theragnostics, an integration of diagnostic and therapeutic capabilities into a single hybrid platform system, has the potential to address these challenges by enabling real-time monitoring of treatment response while allowing endogenously controlled personalized treatment adjustments. In this article, we review the current state-of-the-art in theragnostics for cancer vaccines and RNA therapy, including imaging agents, biomarkers, and other diagnostic tools relevant to cancer, and their application in cancer therapy development and personalization. We also discuss the opportunities and challenges for further development and clinical translation of theragnostics in cancer vaccines.

Ultrasound-Controlled Prodrug Activation: Emerging Strategies in Polymer Mechanochemistry and Sonodynamic Therapy

Ultrasound has gained prominence in biomedical applications due to its noninvasive nature and ability to penetrate deep tissue with spatial and temporal resolution. The burgeoning field of ultrasound-responsive prodrug systems exploits the mechanical and chemical effects of ultrasonication for the controlled activation of prodrugs. In polymer mechanochemistry, materials scientists exploit the sonomechanical effect of acoustic cavitation to mechanochemically activate force-sensitive prodrugs. On the other hand, researchers in the field of sonodynamic therapy adopt fundamentally distinct methodologies, utilizing the sonochemical effect (e.g., generation of reactive oxygen species) of ultrasound in the presence of sonosensitizers to induce chemical transformations that activate prodrugs. This cross-disciplinary review comprehensively examines these two divergent yet interrelated approaches, both of which originated from acoustic cavitation. It highlights molecular and materials design strategies and potential applications in diverse therapeutic contexts, from chemotherapy to immunotherapy and gene therapy methods, and discusses future directions in this rapidly advancing domain.

Computational analysis of controlled drug release from porous polymeric carrier with the aid of Mass transfer and Artificial Intelligence modeling

Controlled release of a desired drug from porous polymeric biomaterials was analyzed via computational method. The method is based on simulation of mass transfer and utilization of artificial intelligence (AI). This study explores the efficacy of three regression models, i.e., Kernel Ridge Regression (KRR), Gaussian Process Regression (GPR), and Gradient Boosting (GB) in determining the concentration of a chemical substance (C) based on coordinates (r, z). Leveraging Firefly Optimization (FFA) for hyperparameter optimization, the models are fine-tuned to maximize their predictive performance. The findings unveil notable disparities in the performance metrics of the models, with GB showcasing the most impressive R2 score of 0.9977, indicative of a remarkable alignment with the data. GPR closely trails with an R2 score of 0.88754, while KRR falls short with an R2 score of 0.76134. Additionally, GB manifests the most modest Mean Squared Error (MSE) and Root Mean Squared Error (RMSE) among the trio of models, further cementing its supremacy in predictive precision. These outcomes accentuate the significance of judiciously selecting regression methodologies and optimization approaches for adeptly modeling intricate spatial datasets.

Mechanochemical Diversity in Block Copolymers

Covalent polymer chains are known to undergo mechanochemical events when subjected to mechanical forces. Such force-coupled reactions, like C-C bond scission in homopolymers, typically occur in a non-selective manner but with a higher probability at the mid-chain. In contrast, block copolymers (BCPs), composed of two or more chemically distinct chains linked by covalent bonds, have recently been shown to exhibit significantly different mechanochemical reactivities and selectivities. These differences may be attributable to the atypical conformations adopted by their chains, compared to the regular random coil. Beyond individual molecules, when BCPs self-assemble into ordered aggregates in solution, the non-covalent interactions between the chains lead to meaningful acceleration in the activation of embedded force-sensitive motifs. Furthermore, the microphase segregation of BCPs in bulk creates periodically dispersed polydomains, locking the blocks in specific conformations which have also been shown to affect their mechanochemical reactivity, with different morphologies influencing reactivity to varying extents. This review summarizes the studies of mechanochemistry in BCPs over the past two decades, from the molecular level to assemblies, and up to bulk materials.

Enhanced Antibacterial Activity of Vancomycin Loaded on Functionalized Polyketones

Today, polymeric drug delivery systems (DDS) appear as an interesting solution against bacterial resistance, having great advantages such as low toxicity, biocompatibility, and biodegradability. In this work, two polyketones (PK) have been post-functionalized with sodium taurinate (PKT) or potassium sulfanilate (PKSK) and employed as carriers for Vancomycin against bacterial infections. Modified PKs were easily prepared by the Paal-Knorr reaction and loaded with Vancomycin at a variable pH. All polymers were characterized by FT-IR, DSC, TGA, SEM, and elemental analysis. Antimicrobial activity was tested against Gram-positive Staphylococcus aureus ATCC 25923 and correlated to the different pHs used for its loading (between 2.3 and 8.8). In particular, the minimum inhibitory concentrations achieved with PKT and PKSK loaded with Vancomycin were similar, at 0.23 μg/mL and 0.24 μg/mL, respectively, i.e., six times lower than that with Vancomycin alone. The use of post-functionalized aliphatic polyketones has thus been demonstrated to be a promising way to obtain very efficient polymeric DDS.