Delivery Of Small Molecule Drugs Research Articles

Antibody-Free Glycogen Nanoparticles Engage Human Immune T Cells for Intracellular Delivery of Small Drugs or mRNA.

T cells play a major role in immune defense against viral infections and diseases such as cancer. Accordingly, developing nanoparticle (NP) systems to effectively deliver therapeutics to T cells is of interest. However, NP-mediated delivery of drugs to T cells is challenging because of the nonphagocytic nature of T cells. To engage T cells and induce cellular internalization, NPs are typically decorated with specific receptor-targeting antibodies, often using laborious and costly procedures. Herein, we report that natural glycogen NPs (i.e., nanosugars) with different sizes (20-80 nm) and surface charges (neutral and positively charged) engage Jurkat T cells, undergo intracellular trafficking, and release encapsulated drug without the use of receptor-targeting antibodies. Specifically, glycogen-resveratrol constructs are employed to reactivate HIV-1 latently infected Jurkat T cells (J-Lat A2) and trigger proviral expression. Both neutral and positively charged glycogen NPs engage with J-Lat A2 cells. Large (84 ± 29 nm) and positively charged (23 ± 5 mV) NPs, denoted phytoglycogen-ethylenediamine (PGEDA) NPs, readily associate with the cell membrane and are internalized (60%) in J-Lat A2 cells but remain confined in the endocytic vesicles, with moderate reactivation of latent HIV-1 (4.7 ± 0.5%). Conversely, small (21 ± 5 nm) and positively charged (10 ± 6 mV) NPs, bovine glycogen-EDA (BGEDA) NPs, associate slowly with T cells but show nearly 100% internalization and efficient endosomal escape properties, resulting in 1.5-fold higher reactivation of latent HIV-1 in T cells. PGEDA NPs and BGEDA NPs are also internalized by primary human T cells (>90% cell association) and enable the transfection of mRNA, with BGEDA NPs showing a 2-fold higher transfection than PGEDA NPs. This work highlights the potential of BGEDA NPs for the effective intracellular delivery of small-molecule drugs and mRNA in T cells.

Stimuli-Responsive Polymers at the Interface with Biology.

There has been growing interest in polymeric systems that break down or undergo property changes in response to stimuli. Such polymers can play important roles in biological systems, where they can be used to control the release of therapeutics, modulate imaging signals, actuate movement, or direct the growth of cells. In this Perspective, after discussing the most important stimuli relevant to biological applications, we will present a selection of recent exciting developments. The growing importance of stimuli-responsive polysaccharides will be discussed, followed by a variety of stimuli-responsive polymeric systems for the delivery of small molecule drugs and nucleic acids. Switchable polymers for the emerging area of therapeutic response measurement in theranostics will be described. Then, the diverse functions that can be achieved using hydrogels cross-linked covalently, as well as by various dynamic approaches will be presented. Finally, we will discuss some of the challenges and future perspectives for the field.

Focused Ultrasound Impels the Delivery and Penetration of Model Therapeutics into Cerebral Cavernous Malformations.

Cerebral cavernous malformations (CCMs) are vascular neoplasms in the brain that can cause debilitating symptoms. Current treatments pose significant risks to some patients, motivating the development of new nonsurgical options. We recently discovered that focused ultrasound-mediated blood-brain barrier opening (FUS) arrests CCM formation and growth. Here, we build on this discovery and assess the ability of FUS to deliver model therapeutics into CCMs. Quantitative T1 mapping MRI sequences were used with 1 kDa (MultiHance; MH) and 17 kDa (GadoSpin D; GDS) contrast agents to assess the FUS-mediated delivery and penetration of model small molecule drugs and biologics, respectively, into CCMs of Krit1 mutant mice. FUS elevated the rate of MH delivery to both the lesion core (4.6-fold) and perilesional space (6.7-fold). Total MH delivery more than doubled in the lesion core and tripled in the perilesional space when FUS was applied immediately prior to MH injection. For the model biologic drug (i.e. GDS), FUS was of greater relative benefit, resulting in 21.7-fold and 3.8-fold delivery increases to the intralesional and perilesional spaces, respectively. FUS is capable of impelling the delivery and penetration of therapeutics into the complex and disorganized CCM microenvironment. Benefits to small molecule drug delivery are more evident in the perilesional space, while benefits to biologic delivery are more evident in CCM cores. These findings, when combined with ability of FUS alone to control CCMs, highlight the potential of FUS to serve as a powerful non-invasive therapeutic platform for CCM.

A new long-acting analgesic formulation for postoperative pain management

Local anesthetics (LA), as part of multimodal analgesia, have garnered significant interest for their role in delaying the initiation of opioid therapy, reducing postoperative opioid usage, and mitigating both hospitalization duration and related expenses. Despite numerous endeavors to extend the duration of local anesthetic effects, achieving truly satisfactory long-acting analgesia remains elusive. Drawing upon prior investigations, vesicular phospholipid gels (VPGs) emerge as promising candidates for extended-release modalities in small-molecule drug delivery systems. Therefore, we tried to use the amphiphilicity of phospholipids to co-encapsulate levobupivacaine hydrochloride and meloxicam, two drugs with different hydrophilicity, to obtain a long-term synergistic analgesic effect. Initially, the physicochemical attributes of the formulation were characterized, followed by an examination of its in vitro release kinetics, substantiating the viability of extending the release duration of the dual drugs. Sequentially, in vivo investigations encompassing pharmacokinetic profiling and assessment of analgesic efficacy were undertaken, revealing a prolonged release duration of up to 120 h and attainment of optimal postoperative analgesia. Subsequently, inquiries into the mechanism underlying synergistic analgesic effects and safety evaluations pertinent to the delivery strategy were pursued. In summation, we successfully developed a promising formulation to achieve long-acting analgesia.

Inhibit diffusion of the small molecule drug lidocaine hydrochloride in dissolving microneedles based on a phase separation approach

Dissolving microneedles (DMNs) have emerged as a promising transdermal drug delivery modality. However, in the case of small-molecule drug delivery, there is a tendency for the drug to disperse from the needle layer into the backing layer, resulting in reduced drug concentration at the needle site and consequently compromising drug delivery efficiency. In this study, lidocaine hydrochloride (Lido) was employed as a model drug to prepare a series of Lido dissolving microneedles (Li-DMNs) through a two-step casting method. We detail their fabrication process and the composition of needle and backing solutions, conduct in vitro characterization, and investigate the impact of viscosity and phase separation effects on drug distribution. Li-DMNs exhibit excellent visual appearance, adequate mechanical strength, favorable puncture permeability, and effective transdermal release property which can effectively facilitate the transdermal delivery of Lido. The phase separation effect significantly impedes Lido diffusion into the backing layer during DMNs preparation. This approach holds immense potential for broad applications and bears great significance in enhancing both drug loading capacity and transdermal delivery efficiency of DMNs.

Chemiexcitation-Triggered Photosensitizer Activation for Photooxidation of Aβ1-42 Aggregates.

Oxidative degradation of the pathogenic amyloid-β-peptide (Aβ) aggregation is an effective and promising method to treat Alzheimer's disease under light irradiation. However, the limited penetration of external light sources into deep tissues has hindered the development of this treatment. Therefore, we have designed an unprecedented chemiluminescence-initiated photodynamic therapy system to replace external laser irradiation, primarily composed of d-glucose-based polyoxalate (G-poly(oxalate)), the novel photosensitizer (BD-Se-QM), and bis [2,4,5-trichloro-6-(pentoxy-carbonyl) phenyl] ester. BD-Se-QM possesses excellent singlet oxygen (1O2) generation efficiency and the ability to photooxidize Aβ1-42 aggregates under white light. G-poly(oxalate) not only helps the nanosystem to cross the blood-brain barrier but also has sufficient oxalate ester groups to significantly enhance the efficiency of chemiluminescence resonance energy transfer. The oxalate ester groups in BD-Se-QM/NPs can chemically react with H2O2 to produce high-energy intermediates that activate BD-Se-QM, which can generate 1O2 to inhibit Aβ1-42 aggregates and also promote microglial uptake of Aβ1-42, reducing the Aβ1-42-induced neurotoxicity. The chemically stimulated nanoplatform not only solves the drug delivery problem but also eliminates the need for external light sources. We anticipate that this chemically excited nanosystem could also be used for targeted delivery of other small molecule drugs.

Bifunctional black phosphorus quantum dots platform: Delivery and remarkable immunotherapy enhancement of STING agonist

Cancer immunotherapy has been developed to improve therapeutic effects for patients by activating the innate immune stimulator of interferon gene (STING) pathway. However, most patients cannot benefit from this therapy, mainly due to the problems of excessively low immune responses and lack of tumor specificity. Herein, we report a solution to these two problems by developing a bifunctional platform of black phosphorus quantum dots (BPQDs) for STING agonists. Specifically, BPQDs could connect targeted functional groups and regulate surface zeta potential by coordinating metal ions to increase loading (over 5 times) while maintaining high universality (7 STING agonists). The controlled release of STING agonists enabled specific interactions with their proteins, activating the STING pathway and stimulating the secretion release of immunosuppressive factors by phosphorylating TBK1 and IFN-IRF3 and secreting high levels of immunostimulatory cytokines, including IL-6, IFN-α, and IFN-β. Moreover, the immunotherapy was enhanced was enhanced mild photothermal therapy (PTT) of BPQDs platform, producing enough T cells to eliminate tumors and prevent tumor recurrence. This work facilitates further research on targeted delivery of small-molecule immune drugs to enhance the development of clinical immunotherapy.

Abstract 6763: A human-relevant vascularized organ-on-a chip platform for anti-tumor drug efficacy and liver injury assessment

Abstract Cancer global burden accounts for 19.3 million new cases and 10 million deaths in 2020. Despite advances on the understanding of disease progression and efforts to find successful therapeutic strategies, most drugs fail in clinical stages. Lack of models with clinical mimicry recapitulating the in vivo pathophysiology and the organ microenvironment where the tumor forms is a key driver reducing the success rate of anti-cancer drugs. Animal models remain the gold standard for preclinical research but fail to recapitulate the complex human tumor microenvironment, a critical component determining tumor development, progression, and response to treatments. Organ-on-a-chip models allow to control the environment and organization of cells in an in vivo-like arrangement by culturing multiple cell types to better replicate human conditions, and by implementing different biochemical and physical stimuli, such as fluid shear stress, chemical/nutrient gradients, and perfusion/flow to recapitulate the human vascular system physiology. We leverage our 3D bioprinting technologies to develop complex vascularized organ-on-a-chip models aimed to recapitulate the tumor and liver niche. Both organ-systems are interconnected by our h-VIOS™ platform, allowing dynamic perfusion for 21 days and enabling the simultaneous assessment of anti-tumor therapeutic efficacy and drug-induced liver injury. Our hydrogels feature a complex perfusable vasculature that interfaces with an interstitial chamber where tissues of interest are grown. The vasculature allows for continued and controlled delivery of nutrients, oxygen, and small molecule drugs. Dextran diffusion studies revealed diffusion coefficients ranging from 43.2 μm2/s (4kDa) to 8 μm2/s (70kDa). Vascular architectures are lined with endothelial cells forming a functional barrier expressing the junctional markers ZO-1 and PECAM-1. Moreover, we can modulate the permeability of our vasculature architecture, allowing the extravasation of immune and cancer cells. PBMC-derived T cells and Jurkat cells undergo transendothelial migration in response to a CXCL12 gradient, highlighting the applicability of our model for immunotherapeutic efficacy studies. The tumor interstitial chamber incorporates co-culture of cancer spheroids or tumoroids, fibroblasts, endothelial and immune cells. Colon carcinoma spheroids effectively integrate into the tumor niche with no growth arrest. The liver model consists of an interstitial chamber with a lobular microstructure supporting the monoculture of primary human hepatocytes, and sustaining their viability and function for 9 days as demonstrated by high albumin production, urea synthesis and CYP activity. Our organ-on-a-chip models are fully customizable and anticipated to contribute to advance personalized medicine and improve clinical translation rates. Citation Format: Juliana Navarro-Yepes, Queeny Dasgupta, Purboja Purkayastha, Kevin Janson, Cassio Mello, Ameya Narkar, Soon Seng Ng, Taci Pereira. A human-relevant vascularized organ-on-a chip platform for anti-tumor drug efficacy and liver injury assessment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6763.

Synthesis of site-specific Fab-drug conjugates using ADP-ribosyl cyclases.

Targeted delivery of small-molecule drugs via covalent attachments to monoclonal antibodies has proved successful in clinic. For this purpose, full-length antibodies are mainly used as drug-carrying vehicles. Despite their flexible conjugation sites and versatile biological activities, intact immunoglobulins with conjugated drugs, which feature relatively large molecular weights, tend to have restricted tissue distribution and penetration and low fractions of payloads. Linking small-molecule therapeutics to other formats of antibody may lead to conjugates with optimal properties. Here, we designed and synthesized ADP-ribosyl cyclase-enabled fragment antigen-binding (Fab) drug conjugates (ARC-FDCs) by utilizing CD38 catalytic activity. Through rapidly forming a stable covalent bond with a nicotinamide adenine dinucleotide (NAD+ )-based drug linker at its active site, CD38 genetically fused with Fab mediates robust site-specific drug conjugations via enzymatic reactions. Generated ARC-FDCs with defined drug-to-Fab ratios display potent and antigen-dependent cytotoxicity against breast cancer cells. This work demonstrates a new strategy for developing site-specific FDCs. It may be applicable to different antibody scaffolds for therapeutic conjugations, leading to novel targeted agents.

Targeting lipid nanoparticles to the blood-brain barrier to ameliorate acute ischemic stroke

Effective delivery of mRNA or small molecule drugs to the brain is a significant challenge in developing treatment for acute ischemic stroke. To address the problem, we have developed targeted nanomedicine to increase drug concentrations in endothelial cells of the blood-brain barrier (BBB) of the injured brain. Inflammation during ischemic stroke causes continuous neuronal death and increase of the infarct volume. To enable targeted delivery to the inflamed BBB, we conjugated lipid nanocarriers with antibodies that bind cell adhesion molecules expressed at the BBB. In the transient middle cerebral artery occlusion mouse model, nanocarriers targeted to VCAM achieved the highest level of brain delivery, nearly 2 orders of magnitude higher than untargeted ones. VCAM-targeted lipid nanoparticles with luciferase-encoding mRNA and Cre-recombinase showed selective expression in the ischemic brain. Anti-inflammatory drugs administered intravenously after ischemic stroke reduced cerebral infarct volume by 62% (IL-10 mRNA) or 35% (dexamethasone) only when they were encapsulated in VCAM-targeted nanocarriers. Thus, VCAM-targeted lipid nanocarriers represent a new platform for strongly concentrating drugs within the compromised BBB of penumbra, thereby ameliorating acute ischemic stroke.

Biodegradable Zwitterionic Polymers as PEG Alternatives for Drug Delivery.

Poly(ethylene glycol) (PEG) is a highly biocompatible and water-soluble polymer that is widely utilized for biomedical applications. Unfortunately, the immunogenicity and antigenicity of PEG severely restrict the biomedical efficacy of pegylated therapeutics. As emerging PEG alternatives, biodegradable zwitterionic polymers (ZPs) have attracted significant interest in recent years. Biodegradable ZPs generally are not only water-soluble and immunologically inert, but also possess a range of favorable biomedically relevant properties, without causing long-term side effects for in vivo biomedical applications. This review presents a systematic overview of recent studies on biodegradable ZPs. Their structural designs and synthetic strategies by integrating biodegradable base polymers with zwitterions are addressed. Their applications in the delivery of small molecule drugs (as mono-drugs or multi-drugs) and proteins are highlighted.

Effects of Drug Conjugation on the Biological Activity of Single-Chain Nanoparticles.

The field of single-chain nanoparticles (SCNPs) continues to mature, and an increasing range of reports have emerged that explore the application of these small nanoparticles. A key application for SCNPs is in the field of drug delivery, and recent work suggests that SCNPs can be readily internalized by cells. However, limited attention has been directed to the delivery of small-molecule drugs using SCNPs. Moreover, studies on the physicochemical effects of drug loading on SCNP performance is so far missing, despite the accepted view that such small nanoparticles should be significantly affected by the drug loading content. To address this gap, we prepared a library of SCNPs bearing different amounts of a covalently conjugated therapeutic drug-sulfasalazine (SSZ). We evaluated the impact of the conjugated drug loading on both the synthesis and biological activity of SCNPs on pancreatic cancer cells (AsPC-1). Our results reveal that covalent drug conjugation to the side chains of the SCNP polymer precursor interferes with chain collapse and cross-linking, which demands optimization of reaction conditions to reach high degrees of cross-linking efficiencies. Small-angle neutron scattering and diffusion-ordered spectroscopy nuclear magnetic resonance (DOSY NMR) analyses reveal that SCNPs with a higher drug loading display larger sizes and looser structures, as well as increased hydrophobicity associated with a higher SSZ content. Increased SSZ loading led to reduced cellular uptake when assessed in vitro, whereby SCNP aggregation on the surface of AsPC-1 cells led to reduced toxicity. This work highlights the effects of drug loading on the drug delivery efficiency and biological behavior of SCNPs.

Biomaterial strategies for regulating the neuroinflammatory response.

Injury and disease in the central nervous system (CNS) can result in a dysregulated inflammatory environment that inhibits the repair of functional tissue. Biomaterials present a promising approach to tackle this complex inhibitory environment and modulate the mechanisms involved in neuroinflammation to halt the progression of secondary injury and promote the repair of functional tissue. In this review, we will cover recent advances in biomaterial strategies, including nanoparticles, hydrogels, implantable scaffolds, and neural probe coatings, that have been used to modulate the innate immune response to injury and disease within the CNS. The stages of inflammation following CNS injury and the main inflammatory contributors involved in common neurodegenerative diseases will be discussed, as understanding the inflammatory response to injury and disease is critical for identifying therapeutic targets and designing effective biomaterial-based treatment strategies. Biomaterials and novel composites will then be discussed with an emphasis on strategies that deliver immunomodulatory agents or utilize cell-material interactions to modulate inflammation and promote functional tissue repair. We will explore the application of these biomaterial-based strategies in the context of nanoparticle- and hydrogel-mediated delivery of small molecule drugs and therapeutic proteins to inflamed nervous tissue, implantation of hydrogels and scaffolds to modulate immune cell behavior and guide axon elongation, and neural probe coatings to mitigate glial scarring and enhance signaling at the tissue-device interface. Finally, we will present a future outlook on the growing role of biomaterial-based strategies for immunomodulation in regenerative medicine and neuroengineering applications in the CNS.

Electrospinning polymersomes into bead-on-string polyethylene oxide fibres for the delivery of biopharmaceuticals to mucosal epithelia

Fibrous mucoadhesive polymer membranes prepared using electrospinning demonstrate many advantages for mucosal drug delivery compared to other formulations. Previous electrospun membrane formulations have been developed mainly for the delivery of small molecule drugs. There remains great potential to further develop the technology for the delivery of vesicular vectors that allow administration of advanced therapeutic agents. However, there are no previous reports demonstrating the release of intact drug delivery vesicles from electrospun materials. Here, we describe incorporation and release of protein-loaded polymersomes from polyethylene oxide (PEO)-based electrospun membranes. Polymersomes comprising a copolymer of glycerol monomethacrylate (GMA) and hydroxypropyl methacrylate (HPMA) were prepared using polymerization-induced self-assembly and incorporated within PEO membranes using bead-on-string electrospinning at approximately 40 % w/w by polymer mass. Super-resolution fluorescence imaging showed that the vesicles remained intact and retained their encapsulated protein load within the fibre beads. Transmission electron microscopy and dynamic light scattering demonstrated that polymersomes retained their morphology following release from the polymer fibres. F(ab) antibody fragments were encapsulated within polymersomes and then electrospun into membranes. 78 ± 13 % of the F(ab) remained encapsulated within polymersomes during electrospinning and retained functionality when released from electrospun membranes, demonstrating that the formulation is suitable for the delivery of biologics. Membranes were non-irritant to the oral epithelium and fluorescence microscopy detected accumulation of polymersomes within the epithelia following application. This innovative drug delivery approach represents a novel and potentially highly useful method for the administration of large molecular mass therapeutic molecules to diseased mucosal sites.

Surface modified cationic PLGA microparticles as long-acting injectable carriers for intra-articular small molecule drug delivery

Controlled local delivery of therapeutics (small molecule drug crystals or biologics) for knee-associated diseases such as osteoarthritis necessitates patient compliance, ensuring that the injected depot does not trigger local tissue inflammation and immune responses. A local drug delivery strategy that releases drug at a controlled rate while ensuring minimal tolerability issues at the injection site would be an appealing paradigm in intra-articular (IA) therapies. Herein, we report the formulation development and characterization of surface modified PLGA microparticles (MPs) through the surface integration of a cationic lipid, DOTAP (1,2-Dioleoyl-3-trimethylammonium propane). Following IA administration, these particles are able to interact with anionic synovial fluid glycosaminoglycans (GAGs) to form an in-situ surface coating in the knee joint, thereby reducing the depot-associated local inflammatory response. The formulated microparticles were about 10–40 µm in size range, with a +19 to +33 mV overall surface charge after DOTAP lipid surface integration. These particles showed preferential surface adhesion with endogenous anionic GAGs (e.g., hyaluronic acid) due to electrostatic interactions in vitro, and approximately 65 % of the model drug triamcinolone acetonide (TCA) was released after 10 weeks in simulated synovial fluid. The uncoated and DOTAP-coated PLGA microparticles had no effect on mouse osteoblast MC3T3 cell viability and human macrophage inflammatory response. Further, DOTAP-coated particles showed a marginal decrease in pro-inflammatory cytokines in naïve rats following knee injection. Together, the results suggest that surface-modified PLGA particles may have promising potential as delivery carriers for long-acting injectables.

Circumventing Physicochemical Barriers of Cyclometalated Gold(III) Dithiocarbamate Complexes with Protein-Based Nanoparticle Delivery to Enhance Anticancer Activity.

Optimizing the bioavailability of drug candidates is crucial to successful drug development campaigns, especially for metal-derived chemotherapeutic agents. Nanoparticle delivery strategies can be deployed to overcome physicochemical limitations associated with drugs to improve bioavailability, pharmacokinetics, efficacy, and minimize toxicity. Biodegradable albumin nanoconstructs offer pragmatic solutions for drug delivery of metallodrugs with translational benefits in the clinic. In this work, we explored a logical approach to investigate and resolve the physicochemical drawbacks of gold(III) complexes with albumin nanoparticle delivery to improve solubility, enhance intracellular accumulation, circumvent premature deactivation, and enhance anticancer activity. We synthesized and characterized stable gold(III) dithiocarbamate complexes with a variable degree of cyclometalation such as phenylpyridine (C^N) or biphenyl (C^C) Au(III) framework and different alkyl chain lengths. We noted that extended alkyl chain lengths impaired the solubility of these complexes in biological media, thus adversely impacting potency. Encapsulation of these complexes in bovine serum albumin (BSA) reversed solubility limitations and improved cancer cytotoxicity by ∼25-fold. Further speciation and mechanism of action studies demonstrate the stability of the compounds and alteration of mitochondria bioenergetics, respectively. We postulate that this nanodelivery strategy is a relevant approach for translational small-molecule gold drug delivery.

Enzyme-Responsive Nanoparticles for the Targeted Delivery of an MMP Inhibitor to Acute Myocardial Infarction.

Herein, we have developed a drug-loaded matrix metalloproteinase (MMP)-responsive micellar nanoparticle (NP) intended for minimally invasive intravenous injection during the acute phase of myocardial infarction (MI) and prolonged retention in the heart for small-molecule drug delivery. Peptide-polymer amphiphiles (PPAs) bearing a small-molecule MMP inhibitor (MMPi), PD166793, were synthesized via ring-opening metathesis polymerization (ROMP) and formulated into spherical micelles by transitioning to aqueous solution. The resulting micellar NPs underwent MMP-induced aggregation, demonstrating enzyme responsiveness. Using a rat MI model, we observed that these NPs were capable of successfully extravasating into the infarcted region of the heart where they were retained due to the active, enzyme-mediated targeting, remaining detectable after 1 week post administration without increasing macrophage recruitment. Furthermore, in vitro studies show that these NPs demonstrated successful drug release following MMP treatment and maintained drug bioactivity as evidenced by comparable MMP inhibition to free MMPi. This work establishes a targeted NP platform for delivering small-molecule therapeutics to the heart after MI, opening possibilities for myocardial infarction treatment.

Delivery of Small-Molecule Drugs and Protein Drugs by Injectable Acid-Responsive Self-Assembled COF Hydrogels for Combinatorial Lung Cancer Treatment.

Covalent organic frameworks (COFs) have revealed enormous application prospects for cancer therapeutics recently, but their assembly systems face considerable challenges, such as the codelivery of hydrophobic and hydrophilic protein drugs with different physicochemical properties for in vivo delivery and release, as well as endosomal/lysosomal escape of protein drugs. To address these issues, we leveraged the high specific surface area, lipotropism, and structural tunability of boronate ester-linked COFs (COF-1) for the construction of advanced drug delivery systems. We first encapsulated the small-molecule drug doxorubicin (DOX) into a lipophilic COF (COF-1@DOX) and immobilized the functional protein drug ribonuclease A (RNase A) on the surface of the COF (RNase A-COF-1@DOX). We then created a novel composite delivery system (RNase A-COF-1@DOX gel) by cross-linking an albumin-oxygenated hydrogel (gel) network into the pores of COFs, allowing targeted codelivery of protein and small-molecule drugs in vivo. Using in-living body and multichannel fluorescence imaging, we analyzed the in vivo codelivery of protein and small-molecule drugs in a Lewis lung carcinoma (LLC) model. Finally, we applied the RNase A-COF-1@DOX gel to treat lung cancer in mice. This study paves an avenue for constructing COF-based drug delivery systems for lung cancer treatment and holds the potential to be extended to other types of cancer for more effective and targeted therapeutic treatments.

Physalis Mottle Virus-Like Nanocarriers with Expanded Internal Loading Capacity.

An ongoing challenge in precision medicine is the efficient delivery of therapeutics to tissues/organs of interest. Nanoparticle delivery systems have the potential to overcome traditional limitations of drug and gene delivery through improved pharmacokinetics, tissue targeting, and stability of encapsulated cargo. Physalis mottle virus (PhMV)-like nanoparticles are a promising nanocarrier platform which can be chemically targeted on the exterior and interior surfaces through reactive amino acids. Cargo-loading to the internal cavity is achieved with thiol-reactive small molecules. However, the internal loading capacity of these nanoparticles is limited by the presence of a single reactive cysteine (C75) per coat protein with low inherent reactivity. Here, we use structure-based design to engineer cysteine-added mutants of PhMV VLPs that display increased reactivity toward thiol-reactive small molecules. Specifically, the A31C and S137C mutants show a greater than 10-fold increased rate of reactivity towards thiol-reactive small molecules, and PhMV Cys1 (A31C), PhMV Cys2 (S137C), and PhMV Cys1+2 (double mutant) VLPs display up to three-fold increased internal loading of the small molecule chemotherapeutics aldoxorubicin and vcMMAE and up to four-fold increased internal loading of the MRI imaging reagent DOTA(Gd). These results further improve upon a promising plant virus-based nanocarrier system for use in targeted delivery of small-molecule drugs and imaging reagents in vivo.

Curcumin delivery using tetrahedral framework nucleic acids enhances bone regeneration in osteoporotic rats

Osteoporosis is an age-related disorder characterized by progressive bone loss and impaired bone regeneration following surgery. The key to the treatment of osteoporosis is the ability to promote bone differentiation of bone marrow mesenchymal stem cells (BMSCs). Curcumin (Cur) is a class of flavonoids with antioxidant and anti-apoptotic ability to promote osteogenesis in osteoporosis. However, Cur has deficiencies such as low cell entry efficiency, easy degradation and hydrophobicity, and new drug delivery strategies are urgently needed to improve the application prospects of Cur. Tetrahedral framework nucleic acids (tFNAs) are a class of anti-inflammatory and antioxidant nanomedicines with spatial structure, as well as small molecule drug delivery systems with good biosafety. tFNAs can bind herbal monomers and small molecule peptides through electrostatic interaction and grooves to promote drug utilization. Meanwhile, tFNAs can connect miRNAs and siRNAs through specially designed sticky ends to regulate the biological functions and activities of cells. In this study, we synthesized tFNAs/Cur complexes, a novel nucleic acid drug system for promoting osteoporotic bone regeneration, to deliver Cur into BMSCs and to exert antioxidant and anti-apoptotic effects. tFNAs/Cur complexes reverse TNF-α-promoted osteogenic inhibition, and facilitate the expression of alkaline phosphatase (Alp), runt-related transcription factor 2 (Runx2), and osterix (Osx). The effect of tFNAs/Cur on the repair of tibial defects in rats with postmenopausal osteoporosis was studied. The experimental group exhibited a higher bone-formation capacity than the control group after 14 and 21 days. In conclusion, tFNAs improve Cur utilization, promote bone repair, and are promising osteoporosis-treatment interventions.