Drug Delivery and Translational Research最新文献

Herein, we report a design for lipid nanoparticles (LNPs) that specifically delivers mRNA to splenic immune cells post intravenous administration for potential anticancer vaccination applications. A diverse library of ionizable lipids was screened in vivo, in combination with various helper lipids, where the composition of LNPs was tweaked to control their in vivo performance. The biodistribution of the LNPs was then investigated at both organ and sub-organ levels. Subsequently, the LNPs were recruited to deliver an anticancer mRNA-based vaccine to mice. The in vivo tropism of the LNPs was dramatically affected by the chemical structure of the ionizable lipids in question, where a model lipid, CL15H6, was recognized as displaying high affinity for the spleen. Further optimization of the composition of the LNPs enabled highly efficient and spleen-selective mRNA delivery, where the optimized CL15H6 LNPs demonstrated a high capacity for homing to splenic antigen-presenting cells (APCs). Furthermore, loading the LNPs with a low dose of ovalbumin-encoding mRNA (mOVA), as a model antigen, protected the mice against OVA-expressing tumor challenges and suppressed the tumor growth in tumor-bearing mice by ~ 75%, which was superior to the results of a clinically-relevant formulation. The CL15H6 LNPs proved to be biosafe upon either acute dose escalation or repeated administrations. The novel and scalable platform reported herein is promising for clinical translation as a neoantigen vaccine.

Coronary microcirculatory dysfunction, affecting over half of acute myocardial infarction (AMI) patients, correlates significantly with AMI prognosis. Nicorandil is an effective drug that markedly improves coronary microcirculation, but current clinical formulations of Nicorandil exhibit a relatively short half-life and lack cardiac selectivity. We formulated and synthesized a variety of mesoporous silica nanoparticles (MSNs) as a drug carrier for loading and delivering Nicorandil. We performed PEG modification on MSNs to enhance their biocompatibility. The SiO₂@PEG showed good serum stability, maintained a uniform spherical structure with a particle size distribution centered within 200 nm and exhibits good dispersibility. SiO₂@PEG-Nicorandil showed no significant impact on AC 16 cells' viability at concentrations up to 50 µg/mL. SiO₂@PEG-Nicorandil significantly enhanced the viability of AC16 cells under oxidative stress conditions, while concurrently reducing intracellular levels of reactive oxygen species (ROS) and Ca²⁺. For the rat coronary microvascular dysfunction model, the SiO₂@PEG-Nicorandil group demonstrated a greater decrease in thrombus formation and the expression of inflammatory cytokines, outperforming the Nicorandil group. In vivo imaging revealed that within one hour post-injection of SiO₂@PEG-Nicorandil-CY7, a notable increase in CY7 fluorescence intensity was observed in the cardiac region compared to surrounding tissues. Drug concentration measurements demonstrated that Nicorandil maintained a stable concentration in cardiac blood at 48 h in the SiO₂@PEG-Nicorandil group. Taken together, SiO₂@PEG-Nicorandil had exhibited superior cardiac-targeting capabilities and sustained-release properties. Within a specific concentration range, it demonstrated enhanced therapeutic effects in the treatment of coronary microcirculation disorders in rats when compared to conventional Nicorandil formulations.

Fetal growth restriction (FGR) affects 5% to 10% of all pregnancies in developed countries and is the second most leading cause of perinatal mortality and morbidity. Life-long consequences of FGR range from learning and behavioral issues to cerebral palsy. To support the newborn brain following FGR, timely and accessible neuroprotection strategies are needed. Curcumin-loaded polymeric nanoparticles, which have been widely explored for the treatment of cancer, neurological disorders, and bacterial infections, have the potential to prevent and mitigate pathogenic inflammatory processes in the FGR brain. Curcumin is a hydrophobic molecule with poor aqueous solubility and therefore has been incorporated into nanoparticles to improve solubility and delivery. However, curcumin loading in many nanoparticles can be limited to 10% by weight or lower. Here, we first optimize the formulation process of curcumin-loaded polymeric nanoparticles to find a tunable, reproducible, and stable formulation with high curcumin loading and encapsulation efficiency. We establish a curcumin formulation with 39% curcumin loading and > 95% curcumin encapsulation efficiency. Using this formulation, we assessed the biodistribution of polymeric nanoparticles in FGR piglets and normally grown (NG) piglets following different administration routes and evaluated brain cellular uptake. We show a significant amount of nanoparticle accumulation in the brain parenchyma of neonatal piglets as early as 4 h after intranasal administration. Nanoparticles colocalized in microglia, a therapeutic target of interest in FGR brain injury. This study demonstrates the potential of curcumin-loaded nanoparticles to treat neuroinflammation associated with FGR in the newborn.

Inefficient and low-precision delivery of exogenous nucleic acids (ENA) severely limits gene therapy on ischemic stroke (IS). Two problems need to be urgently addressed to improve the efficacy of gene therapy; first, the blood brain barrier (BBB) should be open to promote the accumulation of ENA or genetic material carriers in the ischemic brain parenchyma, and second, the efficient delivery of ENA into the ischemic cells. Previous studies applied ultrasonic cavitation either for opening BBB or for inducing sonoporation to deliver genetic materials into cells. However, the effectiveness of the two-step ultrasonic cavitation to deliver ENA in the brain remains unclear, let alone the genetic materials to be controllably delivered into the ischemic brain parenchyma of the IS. This study systematically explored the BBB opening and ENA delivery by the two-step ultrasonic cavitation using artificial acoustic-cationic-polymeric-nanodroplets (ACPNs). The results demonstrated that the first focused ultrasound (FUS), set at parameters of 3.3 MPa, 20 Hz, 200 cycles and 5 s, stimulating intravascular ACPNs cavitation effectively opened BBB to allow nonactivated ACPN extravasation and accumulation into the ischemic brain parenchyma. Then, the extravascular ACPNs enhanced the second ultrasonic cavitation that noninvasively and efficiently controlled ENA delivery to the ischemic cells through sonoporation, particularly applying 3.3 MPa, 60 Hz, 200 cycles and 9 s to control FAM-eNA delivery, and 3.6 MPa, 20 Hz, 200 cycles and 7 s for pEGFP-C1 controlled delivery. Overall, the two-step ultrasonic cavitation represented a potential strategy for IS-targeted ENA controlled delivery.

The intestinal mucus layer serves as a critical first line of defense against external agents, functioning as a barrier to the absorption of drugs, food, and pathogens. While numerous in vitro studies have explored the role of mucus in preventing particle penetration, the effects of flowing luminal material, dislodging of mucus because of induced shear rate by lumen material and interfacial phenomena remain poorly understood. This study introduces a microfluidic approach to simulate the interaction between flowing luminal material and the mucus layer. The approach successfully measures both particle penetration into the mucus layer and the rate of mucus dislodgement by flowing luminal material. A biosimilar mucus model (BSM) and Hank's Balanced Salt Solution (HBSS) were employed as mimics of human intestinal mucus and luminal fluid, respectively. To investigate the effect of viscosity on the particle penetration pattern, two variants of the mucus model were used: BSM-1, representing a low-viscosity mucus model, and BSM-2, representing a high-viscosity mucus model. The velocity fields in the mucus and luminal material were extracted by tracking fluorescent particles. The results revealed significant differences between BSM-1 and BSM-2, attributed to their rheological properties. These findings were further confirmed through an assessment of the viscoelastic properties of the BSM models. The study utilized COMSOL Multiphysics for numerical simulations, successfully predicting experimental outcomes by solving fluid flow equations. Physicochemical characterizations of BSM and HBSS were performed to link the experimental results with numerical simulations, including flow sweep tests, the application of the power-law model for viscosity, and measurements of mucus density and wettability. This study proposes a microfluidic platform for examining mucus dislodgement and particle penetration in both low- and high-viscosity mucus models. The findings offer valuable insights into the intestinal mucus barrier's response to shear stress. The validated numerical approach and physicochemical characterizations provide a foundation for future studies on mucus dislodgement rates and penetration in more complex intestinal geometries and diverse flow conditions.

Polymeric nanocapsules comprised of hydrophobic shells and hollow aqueous interiors are an extremely useful class of nanomaterial, particularly in the encapsulation and controlled delivery of hydrophilic cargo. Generally prepared via droplet or latex templation approaches, polymeric nanocapsules are mostly spherical. Controlling the morphology of hollow nanocapsules is an intriguing design challenge. Non-spherical, or elongated, templates are often inorganic materials which do not directly impart a hollow interior, and their post-polymerization removal is not straightforward. This study outlines a novel strategy for the preparation of elongated nanocapsules, wherein elongated liposomes are deployed as hollow templates. Initially, ciprofloxacin drug nanocrystals were utilized to facilitate the formation of elongated liposomes, followed by adsorption of reversible addition-fragmentation chain transfer (RAFT) oligomers. Subsequent chain-extension polymerization furnished the desired elongated nanocapsule morphology. This proof-of-concept study contributes towards the goal of elongated nanocapsule synthesis, a morphology which can impart improved circulation times in the field of drug delivery.

Solid microneedles allow dermal delivery of drugs that cannot otherwise absorb through skin, via creation of epidermal micropores. The time that the micropores remain open (micropore lifetime) directly impacts drug delivery windows, and darker skin types have extended micropore lifetimes. Here we visualized dermal micropores and measured micropore lifetime in subjects with differing skin pigmentation (ClinicalTrials.gov identifier NCT04867733, registered 29th April 2021). Forty-nine subjects completed the study, self-identifying as Asian, Black, Caucasian, Latinx, and Bi-/multi-racial. Using a colorimeter, skin color was objectively measured and subjects were grouped according to dark (n = 13), medium (n = 19), or light (n = 17) skin. Stainless steel microneedles, 800 μm length, were applied to the arm. Impedance measurements confirmed a breach of skin barrier, suggesting adequate micropore formation. Micropore depth immediately post-microneedle application ranged from 70.3 to 106.6 μm across all subjects (n = 98 total measurements), but was not different between skin color groups, P > 0.05. OCT images were used to calculate micropore closure over 48 h. At 24 h there was no difference in % change in micropore depth between groups. By 48 h there was an 18.1% difference in micropore closure between the lightest and darkest skinned groups, P < 0.05. These data were in agreement with impedance-predicted micropore lifetimes. The longer micropore lifetime in darker skin was independent of micropore depth, and future mechanistic studies of physiological processes underlying these observations would contribute to an understudied area in skin of color research. Proof of concept pharmacokinetics studies would also be useful to investigate the full impact of these differences.

A bupivacaine multivesicular liposomal injectable formulation, Exparel™, is a nonopioid long-acting local analgesic indicated for pain management across and/or post surgeries. For such products, preclinical data is lacking to support bioequivalence determination for potential generic products. Therefore, in the present work, in vivo studies were set up in male Sprague-Dawley rats to understand the in vivo performance of bupivacaine multivesicular liposomes (MVLs), aiming to provide information on bioequivalence establishment between comparator products. Bupivacaine MVLs show a multiphasic release profile, and their pharmacokinetics (PK) may differ with different experimental conditions including doses, administration routes, and sample dilution factors. In this work, compromised bupivacaine MVLs were either generated in lab by freeze-thawing, mechanical agitation, and high-temperature incubation, or chosen from years-old expired batches of Exparel™, for a preliminary investigation on the in vitro and in vivo association. The formulation attributes of different bupivacaine MVLs were characterized, including morphology, particle size distribution, formulation pH, free drug contents, in vitro release, and in vivo PK. In the rat study, even with an observation of inter- and intra-variability in PK, an association between product attributes and in vivo behaviors was demonstrated with bupivacaine MVLs. Overall, investigating the bupivacaine MVLs in vivo is beneficial not only to fill in gaps in preclinical data in the field of bupivacaine MVLs, but also to help pave the path for developing other MVL-related products.

ALK/HDACs dual target inhibitor (PT-54) was a 2,4-pyrimidinediamine derivative synthesized based on the pharmacophore merged strategy that inhibits both anaplastic lymphoma kinase (ALK) and histone deacetylases (HDACs), which has demonstrated significant efficacy in treating multiple cancers. However, its poor solubility in water limited its clinical application. In this study, we prepared PT-54 liposomes (PT-54-LPs) by the membrane hydration method to overcome this defect. The encapsulation efficiency (EE) and particle size were used as evaluation indicators to explore the preparation conditions of PT-54-LPs. The morphology, particle size, EE, drug loading content (DLC), drug release properties, and stability of PT-54-LPs were further investigated. In vitro drug release studies showed that PT-54-LPs exhibited significant slow-release properties compared with free PT-54. PT-54-LPs also showed better tumor inhibitory effects than free PT-54 without significant adverse effects. These results suggested that PT-54-LPs displayed sustained drug release and significantly improved the tumor selectivity of PT-54. Thus, PT-54-LPs showed significant promise in enhancing anticancer efficiency.

Diabetic wound healing remains a healthcare challenge due to co-occurring multidrug-resistant (MDR) bacterial infections and the constraints associated with sustained drug delivery. Here, we integrate two new species of phages designated as PseuPha1 and RuSa1 respectively lysing multiple clinical MDR strains of P. aeruginosa and S. aureus into a novel polyvinyl alcohol-eudragit (PVA-EU^†) nanofiber matrix through electrospinning for rapid diabetic wound healing. PVA-EU^† evaluated for characteristic changes that occurred due to electrospinning and subjected to elution, stability and antibacterial assays. The biocompatibility and wound healing ability of PVA-EU^† were assessed through mouse fibroblast cell line NIH3T3, followed by validation through diabetic mice excision wound co-infected with P. aeruginosa and S. aureus. The electrospinning resulted in the incorporation of ~ 75% active phages at PVA-EU^†, which were stable at 25 °C for 30 days and at 4 °C for 90 days. PVA-EU^† showed sustained release of phages for 18 h and confirmed to be detrimental to both mono- and mixed-cultures of target pathogens. The antibacterial activity of PVA-EU^† remained unaltered in the presence of high amounts of glucose, whereas alkaline pH promoted the activity. The matrix exerted no cytotoxicity on NIH3T3, but showed significant (p < 0.0001) wound healing in vitro and the process was rapid as validated through a diabetic mice model. The sustained release, quick wound closure, declined abundance of target MDR bacteria in situ and histopathological signs of recovery corroborated the therapeutic efficacy of PVA-EU^†. Taken together, our data signify the potential application of PVA-EU^† in the rapid treatment of diabetic wounds without the aid of antibiotics.