Platform For Delivery Of Therapeutics Research Articles

Efficient Nebulization and Pulmonary Biodistribution of Polymeric Nanocarriers in an Acute Lung Injury Preclinical Model

Acute respiratory distress syndrome (ARDS) is a clinical syndrome characterized by acute hypoxemic respiratory failure. Pneumonia and sepsis are the most common causes, turning ARDS into a critical public health problem. Despite recent advances in pharmacological strategies, clinical trials have not demonstrated a reduction in ARDS‐associated mortality. This is in part connected to the singularity of the pulmonary physiological barrier, which hampers drug delivery, specifically at distal areas. To this aim, the use of polymeric nanocarriers as a platform for the efficient delivery of therapeutics to the lungs by nebulization is introduced. Herein, poly(lactic‐co‐glycolic acid) (PLGA) nanocapsules (NCs) loaded with human serum albumin, as an inhalable nanotherapeutic are prepared. The production of stable NCs aerosols in the inhalable range is achieved using a commercial device, while the nanocarrier's physicochemical parameters are only minimally altered after nebulization. Importantly, in vivo studies with healthy and acute lung injury animals show that after inhalation, the NCs are homogeneously distributed throughout the lungs, arriving at the distal areas. The NCs are internalized by alveolar type II cells, avoiding macrophage‐mediated lung clearance. These features make the PLGA NCs excellent vehicles for noninvasive pulmonary delivery, facilitating a ready‐to‐be‐used nanomedicine.

Technology meets clinical practice: Keel Mind as a digital therapy platform

PurposeThe purpose of this paper is to highlight current utilizations of advanced technology within the digital mental health platform Keel Mind.Design/methodology/approachKeel Mind, based out of Ontario, Canada is a therapeutic delivery platform that dually functions to train clinicians and deliver virtual therapy to clients.FindingsFrom personalizing client and therapist matching to using natural language processing (NLP) and artificial intelligence (AI)-driven features Keel Mind supports clinician decision-making to meet the growing mental health needs of the population. Keel Mind functions to provide accessible service, efficiently train high-quality clinicians and enhance clinical outcomes for clients. In a preliminary study within post-secondary students from Ontario, Canada, 90.1% of clients reported liking the platform, and 83.4% reported that they experienced positive mental health outcomes as a result of using Keel Mind.Practical implicationsKeel Mind is a leader within the rapidly developing field of telepsychology and aims to promote positive mental health outcomes worldwide.Originality/valueThis digital showcase is the first published piece of work highlighting the technological capabilities of Keel Mind as a digital therapeutic platform. The intention of this work is to highlight current uses of digital technology within the field of therapeutic practice and to promote technological growth within the field.

Complexation of drug and hapten-conjugated aptamer with universal hapten antibody for pancreatic cancer treatment.

Owing to a lack of reliable markers and therapeutic targets, pancreatic ductal adenocarcinoma (PDAC) remains the most lethal malignant tumor despite numerous therapeutic advances. In this study, we utilized cell-SELEX to isolate a DNA aptamer recognizing the natural conformation of the target on the cell surface. PAp7T8, an aptamer optimized by size and chemical modification, exhibited specific targeting to pancreatic cancer cells and orthotopic xenograft pancreatic tumors. To confer therapeutic functions to the aptamer, we adopted a drug-conjugated oligobody (DOligobody) strategy. Monomethyl auristatin E was used as a cytotoxic drug, digoxigenin acted as a hapten, and the humanized anti-digoxigenin antibody served as a universal carrier of the aptamer. The resulting PAp7T8-DOligobody showed extended in vivo half-life and markedly inhibited tumor growth in an orthotopic pancreatic cancer xenograft model without causing significant toxicity. Therefore, PAp7T8-DOligobody represents a promising novel therapeutic delivery platform for PDAC.

Plasma polymerized nanoparticles are a safe platform for direct delivery of growth factor therapy to the injured heart.

Introduction: Heart failure due to myocardial infarction is a progressive and debilitating condition, affecting millions worldwide. Novel treatment strategies are desperately needed to minimise cardiomyocyte damage after myocardial infarction and to promote repair and regeneration of the injured heart muscle. Plasma polymerized nanoparticles (PPN) are a new class of nanocarriers which allow for a facile, one-step functionalization with molecular cargo. Methods: Here, we conjugated platelet-derived growth factor AB (PDGF-AB) to PPN, engineering a stable nano-formulation, as demonstrated by optimal hydrodynamic parameters, including hydrodynamic size distribution, polydisperse index (PDI) and zeta potential, and further demonstrated safety and bioactivity in vitro and in vivo. We delivered PPN-PDGF-AB to human cardiac cells and directly to the injured rodent heart. Results: We found no evidence of cytotoxicity after delivery of PPN or PPN-PDGFAB to cardiomyocytes in vitro, as determined through viability and mitochondrial membrane potential assays. We then measured contractile amplitude of human stem cell derived cardiomyocytes and found no detrimental effect of PPN on cardiomyocyte contractility. We also confirmed that PDGF-AB remains functional when bound to PPN, with PDGF receptor alpha positive human coronary artery vascular smooth muscle cells and cardiac fibroblasts demonstrating migratory and phenotypic responses to PPN-PDGF-AB in the same manner as to unbound PDGF-AB. In our rodent model of PPN-PDGF-AB treatment after myocardial infarction, we found a modest improvement in cardiac function in PPN-PDGF-AB treated hearts compared to those treated with PPN, although this was not accompanied by changes in infarct scar size, scar composition, or border zone vessel density. Discussion: These results demonstrate safety and feasibility of the PPN platform for delivery of therapeutics directly to the myocardium. Future work will optimize PPN-PDGF-AB formulations for systemic delivery, including effective dosage and timing to enhance efficacy and bioavailability, and ultimately improve the therapeutic benefits of PDGF-AB in the treatment of heart failure cause by myocardial infarction.

Nanomaterial-assisted theranosis of bone diseases.

Bone-related diseases refer to a group of skeletal disorders that are characterized by bone and cartilage destruction. Conventional approaches can regulate bone homeostasis to a certain extent. However, these therapies are still associated with some undesirable problems. Fortunately, recent advances in nanomaterials have provided unprecedented opportunities for diagnosis and therapy of bone-related diseases. This review provides a comprehensive and up-to-date overview of current advanced theranostic nanomaterials in bone-related diseases. First, the potential utility of nanomaterials for biological imaging and biomarker detection is illustrated. Second, nanomaterials serve as therapeutic delivery platforms with special functions for bone homeostasis regulation and cellular modulation are highlighted. Finally, perspectives in this field are offered, including current key bottlenecks and future directions, which may be helpful for exploiting nanomaterials with novel properties and unique functions. This review will provide scientific guidance to enhance the development of advanced nanomaterials for the diagnosis and therapy of bone-related diseases.

Evaluation of Nonmodified Wireframe DNA Origami for Acute Toxicity and Biodistribution in Mice.

Wireframe DNA origami can be used to fabricate virus-like particles for a range of biomedical applications, including the delivery of nucleic acid therapeutics. However, the acute toxicity and biodistribution of these wireframe nucleic acid nanoparticles (NANPs) have not been previously characterized in animal models. In the present study, we observed no indications of toxicity in BALB/c mice following a therapeutically relevant dosage of nonmodified DNA-based NANPs via intravenous administration, based on liver and kidney histology, liver and kidney biochemistry, and body weight. Further, the immunotoxicity of these NANPs was minimal, as indicated by blood cell counts and type-I interferon and pro-inflammatory cytokines. In an SJL/J model of autoimmunity, we observed no indications of NANP-mediated DNA-specific antibody response or immune-mediated kidney pathology following the intraperitoneal administration of NANPs. Finally, biodistribution studies revealed that these NANPs accumulate in the liver within one hour, concomitant with substantial renal clearance. Our observations support the continued development of wireframe DNA-based NANPs as next-generation nucleic acid therapeutic delivery platforms.

Photomodulated Extrusion as a Localized Endovascular Hydrogel Deposition Method.

Minimally invasive endovascular embolization is used to treat a wide range of diseases in neurology, oncology, and trauma where the vascular morphologies and corresponding hemodynamics vary greatly. Current techniques based on metallic coils, flow diverters, liquid embolics, and suspended microspheres are limited in their ability to address a wide variety of vasculature and can be plagued by complications including distal migration, compaction, and inappropriate vascular remodeling. Further, these endovascular devices currently offer limited therapeutic functions beyond flow control such as drug delivery. Herein, a novel in situ microcatheter-based photomodulated extrusion approach capable of dynamically tuning the physical and morphological properties of injectable hydrogels, optimizing for local hemodynamic environment and vascular morphology, is proposed and demonstrated. A shear thinning and photoactivated poly(ethylene glycol diacrylate)-nanosilicate (PEGDA-nSi) hydrogel is used to demonstrate multiple extrusion modes which are controlled by photokinetics and device configurations. Real-time photomodulation of injected hydrogel viscosity and modulus is successfully used for embolization in various vasculatures, including high-flow large vessels and arterial-to-arterial capillary shunts. Furthermore, a generalizable therapeutic delivery platform is proposed by demonstrating a core-shell structured extrusion encapsulating doxorubicin to achieve a more sustained release compared to unencapsulated payload.

Semaphorin 3A delivered by a rapidly polymerizing click hydrogel overcomes impaired implant osseointegration in a rat type 2 diabetes model.

Semaphorin 3A (sema3A) is an osteoprotective factor that enhances bone formation while inhibiting osteoclast bone resorption. It is produced by rat calvarial osteoblasts cultured on grit-blasted/acid-etched microtextured (SLA) titanium surfaces at higher levels than on tissue culture polystyrene, suggesting that it may improve performance of titanium implants in vivo, particularly in conditions characterized by compromised bone quality. To test this, we established a clinically relevant type 2 diabetes mellitus (T2DM) rat model and used a non-toxic click hydrogel that rapidly polymerizes in situ (GEL) to provide localized controlled delivery of sema3A. In vitro studies confirmed that sema3A released from GEL was biologically active, increasing osteoblast differentiation of a pre-osteoblast cell-line. Whereas increased sema3A production was not observed in T2DM calvarial osteoblasts cultured on SLA, exogenous sema3A enhanced surface-induced osteoblast differentiation, indicating that it would be a viable candidate for in vivo use. Delivery of sema3A either by GEL or by local injection to bone defects enhanced osseointegration of SLA implants in the T2DM rats. Trabecular bone mass and bone-to-implant contact were decreased in T2DM rats compared to normal rats; sema3A delivered locally improved both parameters. These findings suggest that reduced trabecular bone contributes to poor osseointegration in T2DM patients and support GEL as a promising treatment option for sustained release of therapeutic doses of sema3A. Moreover, using this clinically translatable T2DM model and developing a biocompatible, Cu-free click chemistry hydrogel platform for the non-invasive delivery of therapeutics has major implications for regenerative medicine as a whole. STATEMENT OF SIGNIFICANCE: Osseointegration is compromised in patients with poor bone quality due to conditions like type 2 diabetes mellitus (T2DM). Previously, we showed that semaphorin 3A (sema3A) production is increased when human bone marrow stromal cells are cultured on titanium substrates that support osseointegration in vivo, suggesting it may enhance peri-implant osteogenesis in diabetes. Here we established a spontaneously developing T2DM rat model with clinical translatability and used it to assess sema3A effectiveness. Sema3A was delivered to the implant site via a novel copper-free click hydrogel, which has minimal swelling behavior and superior rheological properties. Osseointegration was successfully restored, and enhanced compared to burst release through injections. This study provides scientific evidence for using sema3A to treat impaired osseointegration in T2DM patients.

Frontiers in nonviral delivery of small molecule and genetic drugs, driven by polymer chemistry and machine learning for materials informatics.

Materials informatics (MI) has immense potential to accelerate the pace of innovation and new product development in biotechnology. Close collaborations between skilled physical and life scientists with data scientists are being established in pursuit of leveraging MI tools in automation and artificial intelligence (AI) to predict material properties in vitro and in vivo. However, the scarcity of large, standardized, and labeled materials data for connecting structure-function relationships represents one of the largest hurdles to overcome. In this Highlight, focus is brought to emerging developments in polymer-based therapeutic delivery platforms, where teams generate large experimental datasets around specific therapeutics and successfully establish a design-to-deployment cycle of specialized nanocarriers. Three select collaborations demonstrate how custom-built polymers protect and deliver small molecules, nucleic acids, and proteins, representing ideal use-cases for machine learning to understand how molecular-level interactions impact drug stabilization and release. We conclude with our perspectives on how MI innovations in automation efficiencies and digitalization of data-coupled with fundamental insight and creativity from the polymer science community-can accelerate translation of more gene therapies into lifesaving medicines.

Engineering a Novel Self-Assembled Multi-siRNA Nanocaged Architecture with Controlled Enzyme-Mediated siRNA Release.

The RNA interference (RNAi) chemical and structural design space has evolved since its original definitions. Although this has led to the development of RNAi molecules that are starting to address the issues of silencing efficiency and delivery to target organs and cells, there is an on-going interest to improve upon their properties to attain wider therapeutic applicability. Taking advantage of the flexibility given by DNA and RNA structural and chemical properties, we here investigated unconventional RNAi encoding structures, designated by caged-siRNA structures (CsiRNAs), to explore novel features that could translate into advantageous properties for cellular delivery and intracellular activity. Using the principles of controlled nucleic acid self-assembly, branched DNA-RNA hybrid intermediates were formed, ultimately leading to the assembly of a "closed" structure encompassing multiple RNAi units. The RNAi active regions are further triggered by an encoded RNAse H-mediated release mechanism, while the overall structure possesses easily addressable anchors for hybridization-based functionalization with active biological moieties. We confirmed the production of correct structures and demonstrated that the encoded RNAi sequences maintain gene silencing activity even within this novel unconventional nanoarchitecture, aided by the intracellularly triggered RNAse H release mechanism. With this design, functionalization is easily achieved with no negative effects on the silencing activity, warranting further development of these novel molecular structures as a multi-RNAi platform for therapeutic delivery.

Developing a Translational Platform for Therapeutic Delivery of Image-Guided Ultra-Hypofractionated Prostate-Directed Radiotherapy in Orthotopic Prostate Cancer Models

<h3>Purpose/Objective(s)</h3> Prostate stereotactic body radiation therapy (SBRT) is rapidly evolving as a standard-of-care option for definitive management of localized prostate cancer. To our knowledge, there are currently no preclinical models that deliver SBRT-like treatment to orthotopic prostate tumors that reflect the precision and accuracy of clinical treatment. The objective of this study is to develop and credential a small animal radiation research platform (SAARP)-based therapeutic model of image-guided ultra-hypofractionated prostate-directed radiotherapy (RT) that is dosimetrically accurate with clinically relevant radiation doses. <h3>Materials/Methods</h3> Orthotopic prostate tumors are established following intraprostatic injection of 2 × 10⁵ PC3 tumor cells (stably expressing luciferase following lentiviral transduction) into the dorsal aspect of the prostate gland of nude mice. Serial orthotopic tumor growth is monitored with weekly bioluminescence (BLI) and Q2week MRI. Reverse-contrast cone-beam CT imaging (CBCT) is performed with intraperitoneal injection of 2mL of 60% omnipaque immediately prior to CBCT. Pre-treatment MRI is fused to CBCT to facilitate delineation of organs-at-risk (rectum, bladder, bowel bag) and target (prostate) for contouring. Individual plans (generally 4 or 5-field coplanar beam arrangement) were generated to target the prostate (SV not intentionally targeted) and avoid OAR. The SARRP was used to deliver 36.25Gy in 5 fractions of prostate-directed RT [day 30] and weekly serial BLI + MRI used to assess treatment response. <h3>Results</h3> Reverse contrast CBCT imaging +/- MR fusion was sufficient for OAR and target delineation and facilitated daily image-guidance whereas CBCT alone was insufficient. Radiation dosimetry noted a positive association between pH2AX mean fluorescence intensity (MFI) with escalating radiation doses of 0Gy, 2Gy, 8Gy and 20Gy. Preliminary DVH analysis of therapeutically irradiated orthotopic prostate tumors and adjacent OARs noted CTV prostate coverage>90%, rectumD50%<4Gy and bladderD50<4Gy in 3 of 5 serial fractions delivered. Surgically implanted intraprostatic TLD were harvested post-RT to confirm and quantify intraprostatic radiation dose received. Therapeutic response was observed with significantly lower luminescence counts in irradiated (n=13) vs non-irradiated controls (n=11) [p=0.049] and no treatment-related deaths were observed in irradiated mice. <h3>Conclusion</h3> We have developed a preclinical workflow for image-guided delivery of ultra-hypofractioned radiotherapy of orthotopic prostate tumors with ongoing optimization goals to achieve clinically relevant dose constraints and target coverage of NRG GU-005. Ongoing translational work involves DNA damage response assessment in irradiated prostate and adjacent organs-at-risks. This platform is now being explored in immunocompetent settings to better understand intraprostatic immune responses induced by prostate-directed RT.

Abstract P2008: Hypertrophic Cardiomyopathy Treatment Using Ultrasound And Microbubbles

Introduction: Hypertrophic cardiomyopathy is a disease characterized by the abnormal growth of cardiomyocytes (CMs), a marker of which is the early downregulation of miR-1. The delivery of miR-1 to hypertrophic CMs presents as a promising treatment strategy, however there are still limitations in the safe and efficient delivery of gene therapeutics.Ultrasound (US) and microbubbles is an emerging approach to site-specific gene delivery. Microbubbles have long been employed in clinical cardiology as a diagnostic contrast agent. Recent work has demonstrated that under specific conditions, they are capable of forming temporary pores on neighboring cell membranes, allowing the delivery of otherwise impermeable macromolecules. This presents an exciting approach to the treatment of cardiovascular disease (CVD) as a targeted and inherently image-guided therapeutic delivery platform. Objective: The goal of this study is to determine the feasibility of viable US and microbubble mediated delivery of miR-1 to hypertrophic CMs with a view towards reversing the disease. Secondly, we aim to show a correlation between bubble echoes and resulting gene delivery to introduce clinical metrics for the translation of this technique. Methods: CMs were harvested from neonatal rat pups (1-3 days old) and hypertrophied using phenylephrine (100μM). Suspension of healthy or diseased CMs, microbubbles and free miR-1 were placed in a chamber within a 37°C degassed water bath. These samples were insonicated at a mechanical index (MI) ranging from 0.063-0.25 for 2 minutes (20 cycles; 5 kHz PRF) and bubble echoes were recorded via a co-aligned transducer to be processed offline. miR-1 delivery was confirmed with RT-qPCR, cell viablity assesed with MTT, protein expression was measured by immunoblotting and cell size via microscopy. All experiments preformed are at least n=2 independent samples. Result and Conclusion: Treated healthy and diseased CMs demonstrate an upregulation in miR-1 with increasing MI, from 0.063 to 0.188. At MI=0.12, a 2.22 and 1.95-fold increase in miR-1 was shown in diseased and healthy CMs respectively ( p= 0.07, p= 0.02) while maintaining viability (86% and 96% respectively). These miR-1 levels begin to show the reversal of hypertrophy as quantified by increases in target protein expression (1.93-fold in TWF1; 1.38-fold in MEF2A; 1.36-fold in CX43) and cell size decrease (16%, p =0.035) back towards heathy levels. Echo data highlights that relative miR-1 expression positively correlates with bubble disruption ( r =0.76, p =0.04), suggesting a means by which treatment efficiency can be monitored in a clinical setting.In conclusion, we demonstrated that US and microbubbles can be used to successfully delivery miR-1 to CMs, with the potential to reverse the disease phenotype. These findings demonstrate the feasibility of US as an image-guided delivery method for molecular therapeutics in CVD.

Controlling Nuclease Degradation of Wireframe DNA Origami with Minor Groove Binders.

Viruslike particles (VLPs) fabricated using wireframe DNA origami are emerging as promising vaccine and gene therapeutic delivery platforms due to their programmable nature that offers independent control over their size and shape, as well as their site-specific functionalization. As materials that biodegrade in the presence of endonucleases, specifically DNase I and II, their utility for the targeting of cells, tissues, and organs depends on their stability in vivo. Here, we explore minor groove binders (MGBs) as specific endonuclease inhibitors to control the degradation half-life of wireframe DNA origami. Bare, unprotected DNA-VLPs composed of two-helix edges were found to be stable in fetal bovine serum under typical cell culture conditions and in human serum for 24 h but degraded within 3 h in mouse serum, suggesting species-specific endonuclease activity. Inhibiting endonucleases by incubating DNA-VLPs with diamidine-class MGBs increased their half-lives in mouse serum by more than 12 h, corroborated by protection against isolated DNase I and II. Our stabilization strategy was compatible with the functionalization of DNA-VLPs with HIV antigens, did not interfere with B-cell signaling activity of DNA-VLPs in vitro, and was nontoxic to B-cell lines. It was further found to be compatible with multiple wireframe DNA origami geometries and edge architectures. MGB protection is complementary to existing methods such as PEGylation and chemical cross-linking, offering a facile protocol to control DNase-mediated degradation rates for in vitro and possibly in vivo therapeutic and vaccine applications.

Gene Therapy for Brain Tumors: Identification of New Therapeutic Targets Based on RNA Structure

This project is to develop therapies to bypass challenges to effective and continuous drug delivery to the brain, for the treatment of glioblastoma multiforme (GBM). Currently, individuals diagnosed with GBM have a short life expectancy of 12‐14 months. Our approach has the potential to deliver one single dose of gene therapy directly to the GBM tumor environment and block the production of cancer‐driving genes. Epidermal growth factor receptor (EGFR) is dysregulated in 57% of all GBM. Our approach uses an adeno‐associated virus gene transfer vector encoding RNA therapeutics targeting critical elements of the EGFR pre‐mRNA transcript. We have examined the ‘pre‐mRNA structurome’ of EGFR to evaluate the accessibility of targetable regions. To advance our therapeutic strategy, we have analyzed the secondary structure of the EGFR transcript using selective 2’ hydroxyl acylation and primer extension followed by mutational profiling (SHAPE‐MaP). SHAPE‐MaP reactivity profiles were generated revealing the structure of splicing and cryptic polyadenylation signal (PAS) elements within the targeted region. We identified enhancer binding motifs surrounding the 5’ splice site and hidden elements of a cryptic polyadenylation signal. Based on these structural profiles, we generated RNA therapies that interact with structural elements to unravel the hidden polyadenylation signal with the potential to activate expression of the short therapeutic isoform. In this project, we cloned these therapies into our therapeutic delivery platform and tested their efficacy to alter EGFR gene expression in tissue culture cells. Currently, we are evaluating in vitro, the therapeutic RNA interaction with the target sequence of the EGFR pre‐mRNA transcript.

RNA Therapeutics for Brain Tumors: Targeting Pre‐mRNA Splicing Motifs to Generate Therapeutic Gene Isoforms

Individuals diagnosed with glioblastoma multiforme (GBM) have a short life expectancy of 12‐15 months. This project is to develop therapies for effective and continuous drug delivery to the brain, targeting cancer‐driving genes. Tumor cell proliferation in GBM is often stimulated by epidermal growth factor receptor (EGFR) and is important for tumor cell survival. In our lab, we are developing RNA therapies to alter the splicing mechanism of EGFR to block its activation, thus stop tumor cell growth. Our approach uses an adeno‐associated virus gene transfer vector encoding RNA therapeutics targeting critical elements of the EGFR pre‐mRNA transcript. In this project, we cloned therapies into our therapeutic delivery platform and tested their efficacy to alter EGFR gene expression in tissue culture cells. We have found that our therapies have led to a shift in Intron 10A retention increasing alternative intronic polyadenylation generating a short soluble therapeutic decoy. Our antisense therapies targeted the EGFR pre‐mRNA transcript, specifically, regions of exon 10 and intron 10. Therapies were either designed to enhance recognition of the alternative intronic polyadenylation signal or block recognition of canonical exon 10/exon 11 splicing. We targeted the Exonic Splicing Enhancer (ESE) wild‐type 5’ Splice Site (wt‐5’SS) of exon 10, and the regions surrounding the alternative intronic polyadenylation signal. Each target showed a significant increase in intron retention. Targeting the ESE showed a 5‐fold increase in intron retention (p &lt; 0.04), the wt‐5’SS was 15‐fold (p &lt; 0.001), and the region surrounding the alternative intronic polyadenylation signal showed the strongest effect, with greater than 60‐fold increase in intron retention (p &lt; 0.002). Currently, we are examining additional antisense therapies, as well as generation of the therapeutic soluble decoy protein using ELISA.

Cross-linked Histone as a Nanocarrier for Gut Delivery of Hydrophobic Cargos.

Delivering hydrophobic molecules through the intestine can be challenging due to limited cargo solubility and the harsh biochemical environment of the stomach. Here, we show that a protein-based nanocarrier system based on the abundant protein histone and the natural cross-linker genipin can deliver hydrophobic cargos, such as dyes and therapeutic molecules, through the gastrointestinal tract. Using hydrophobic near-infrared dyes as model cargos, a panel of potential protein carriers was screened, and histone was identified as the one with the best loading capability. The resulting nanoparticles had a positive ζ potential and were mucoadhesive. Cross-linking of the amine-rich nanocarrier with genipin was particularly effective relative to other proteins and increased the stability of the system during incubation with pepsin. Cross-linking was required for successful delivery of a hydrophobic dye to the colon of mice after oral gavage. To assess the platform for therapeutic delivery, another hydrophobic model compound, curcumin, was delivered using cross-linked histone nanoparticles in a murine colitis model and significantly alleviated the disease. Taken together, these results demonstrate that histone is a cationic, mucoadhesive, and cross-linkable protein nanocarrier that can be considered for oral delivery.

A general prodrug nanohydrogel platform for reduction-triggered drug activation and treatment of taxane-resistant malignancies

Chemotherapy has been widely used for treating the vast majority of cancer patients. Unfortunately, only a fraction of patients can respond to chemotherapies, but these patients still experience severe side effects. In this context, a wide range of nanotherapeutic platforms have been developed with the aim of improving treatment outcomes while reducing drug toxicities. Nanohydrogels are highly appealing “smart” biocompatible and biodegradable vehicles for either local or systemic delivery of bioactive compounds. Here, we developed prodrug hydrogelators that can undergo one-step distillation-precipitation polymerization to form systemically injectable nanohydrogels. The optimized nanohydrogels were capable of rapidly releasing active agents (e.g., the cytotoxic agent cabazitaxel or the PI3K molecular inhibitor PI103) in response to the reducing tumor microenvironment, while drug release was very slow in the absence of the reductive reagent glutathione. Cabazitaxel-loaded nanogels showed preferential tumor accumulation, and administration of nanogels produced durable tumor regression in a docetaxel-resistant cervical tumor xenograft-bearing mouse model. More significantly, nanogel-based therapy was proven to demonstrate a higher safety profile than solution-based free cabazitaxel. Collectively, this study provides an alternative formulation that meets the essential requirements of high stability in the blood, spontaneous drug release at diseased sites, favorable safety in vivo, and translational capacity for further investigations. Statement of significanceChemotherapy remains a considerable challenge and only a fraction of patients can respond to chemotherapies. Here we report an intratumoral reducing agent-activatable, tumor-targeting prodrug nanogel platform for therapeutic delivery. To this end, two anticancer agents (e.g., cytotoxic cabazitaxel or PI3K molecular inhibitor PI103) are tested. Prodrug nanogels are stable in the blood but performed reduction-triggered release of chemically unmodified drug molecules in cancerous tissues. Cabazitaxel-loaded nanogels exhibit satisfactory anticancer performance in a preclinical docetaxel-resistant tumor model. This is a practical and expedient approach that combines the prodrug strategy and nanogel scaffold to re-engineer a hydrophobic and toxic anticancer drug. The approach also is broadly applicable for the formulation of other agents to improve the therapeutic index.

Modified Gold Nanoparticles for Efficient Delivery of Betulinic Acid to Cancer Cell Mitochondria.

Advances in nanomedicine have seen the adaptation of nanoparticles (NPs) for subcellular delivery for enhanced therapeutic impact and reduced side effects. The pivotal role of the mitochondria in apoptosis and their potential as a target in cancers enables selective induction of cancer cell death. In this study, we examined the mitochondrial targeted delivery of betulinic acid (BA) by the mitochondriotropic TPP+-functionalized epigallocatechin gallate (EGCG)-capped gold NPs (AuNPs), comparing the impact of polyethylene glycol (PEG) and poly-L-lysine-graft-polyethylene glycol (PLL-g-PEG) copolymer on delivery efficacy. This included the assessment of their cellular uptake, mitochondrial localization and efficacy as therapeutic delivery platforms for BA in the human Caco-2, HeLa and MCF-7 cancer cell lines. These mitochondrial-targeted nanocomplexes demonstrated significant inhibition of cancer cell growth, with targeted nanocomplexes recording IC50 values in the range of 3.12–13.2 µM compared to that of the free BA (9.74–36.31 µM) in vitro, demonstrating the merit of mitochondrial targeting. Their mechanisms of action implicated high amplitude mitochondrial depolarization, caspases 3/7 activation, with an associated arrest at the G0/G1 phase of the cell cycle. This nano-delivery system is a potentially viable platform for mitochondrial-targeted delivery of BA and highlights mitochondrial targeting as an option in cancer therapy.

The Role of Hyaluronic Acid in Intervertebral Disc Regeneration

Intervertebral disc (IVD) degeneration is a leading cause of low back pain worldwide, incurring a significant burden on the healthcare system and society. IVD degeneration is characterized by an abnormal cell-mediated response leading to the stimulation of different catabolic biomarkers and activation of signalling pathways. In the last few decades, hyaluronic acid (HA), which has been broadly used in tissue-engineering, has popularised due to its anti-inflammatory, analgesic and extracellular matrix enhancing properties. Hence, there is expressed interest in treating the IVD using different HA compositions. An ideal HA-based biomaterial needs to be compatible and supportive of the disc microenvironment in general and inhibit inflammation and downstream cascades leading to the innervation, vascularisation and pain sensation in particular. High molecular weight hyaluronic acid (HMW HA) and HA-based biomaterials used as therapeutic delivery platforms have been trialled in preclinical models and clinical trials. In this paper, we reviewed a series of studies focused on assessing the effect of different compositions of HA as a therapeutic, targeting IVD degeneration. Overall, tremendous advances have been made towards an optimal form of a HA biomaterial to target specific biomarkers associated with IVD degeneration, but further optimization is necessary to address regeneration.

Zinc imidazolate framework-8 as a promising nitric oxide carrier

Uncontrollable release and unexpected release limit the use of nitric oxide (NO). To overcome this problem, we introduce ZIF-8 as a pH-responsive NO carrier. The flexible framework of ZIF-8 under the high-pressure condition causes the physically NO adsorption inside the SOD cage. ZIF-8 maintain the excellent gas storage ability under the physiological environment. The results show good pH-responsive ability. The gas could not be released out until the particle is in an acid condition. At low pH conditions, half of the gas is released in 1% of the total release duration. Interestingly, the half-release (t1/2) increases to 10% when the phosphate species exist in the acid surrounding. The gradual release can occur under neutral conditions with the existence of phosphate (t1/2 33%). From these results, we expect this ZIF-8 loading NO nanoparticles is lead to the design of innovative gas therapeutic delivery platforms using the advantage of the flexible framework for loading and releasing the gas molecule.