Bioactive sucralfate-based microneedles promote wound healing through reprogramming macrophages and protecting endogenous growth factors.

Impaired wound healing due to insufficient cell proliferation and angiogenesis is a significant physical and psychological burden to patients worldwide. Therapeutic delivery of exogenous growth factors (GFs) at high doses for wound repair is non-ideal as GFs have poor stability in proteolytic wound environments. Here, we present a two-stage strategy using bioactive sucralfate-based microneedle (SUC-MN) for delivering interleukin-4 (IL-4) to accelerate wound healing. In the first stage, SUC-MN synergistically enhanced the effect of IL-4 through more potent reprogramming of pro-regenerative M2-like macrophages via the JAK-STAT pathway to increase endogenous GF production. In the second stage, sucralfate binds to GFs and sterically disfavors protease degradation to increase bioavailability of GFs. The IL-4/SUC-MN technology accelerated wound healing by 56.6 % and 46.5 % in diabetic mice wounds and porcine wounds compared to their respective untreated controls. Overall, our findings highlight the innovative use of molecular simulations to identify bioactive ingredients and their incorporation into microneedles for promoting wound healing through multiple synergistic mechanisms.

Bioactive coating provides antimicrobial protection through immunomodulation and phage therapeutics.

Medical implant-associated infections (IAI) is a growing threat to patients undergoing implantation surgery. IAI prevention typically relies on medical implants endowed with bactericidal properties achieved through surface modifications with antibiotics. However, the clinical efficacy of this traditional paradigm remains suboptimal, often necessitating revision surgery and posing potentially lethal consequences for patients. To bolster the existing anti-IAI arsenal, we propose herein a chitosan-based bioactive coating, i.e., ChitoAntibac, which exerts bacteria-inhibitory effects either through immune modulation or phage-directed microbial clearance, without relying on conventional antibiotics. The immuno-stimulating effects and phage-induced bactericidal properties can be tailored by engineering the loading dynamic of macrophage migration inhibitory factor (MIF), which polarizes macrophages towards the proinflammatory subtype (M1) with enhanced bacterial phagocytosis, and Staphylococcal Phage K, resulting in rapid and targeted pathogenic clearance (>99.99%) in less than 8 h. Our innovative antibacterial coating opens a new avenue in the pursuit of effective IAI prevention through immuno-stimulation and phage therapeutics.

Mechano-Activated Cell Therapy for Accelerated Diabetic Wound Healing.

Chronic diabetic wounds are a significant global healthcare challenge. Current strategies, such as biomaterials, cell therapies, and medical devices, however, only target a few pathological features and have limited efficacy. A powerful platform technology combining magneto-responsive hydrogel, cells, and wireless magneto-induced dynamic mechanical stimulation (MDMS) is developed to accelerate diabetic wound healing. The hydrogel encapsulates U.S. Food and Drug Administration (FDA)-approved fibroblasts and keratinocytes to achieve ∼3-fold better wound closure in a diabetic mouse model. MDMS acts as a nongenetic mechano-rheostat to activate fibroblasts, resulting in ∼240% better proliferation, ∼220% more collagen deposition, and improved keratinocyte paracrine profiles via the Ras/MEK/ERK pathway to boost angiogenesis. The magneto-responsive property also enables on-demand insulin release for spatiotemporal glucose regulation through increasing network deformation and interstitial flow. By mining scRNAseq data, a mechanosensitive fibroblast subpopulation is identified that can be mechanically tuned for enhanced proliferation and collagen production, maximizing therapeutic impact. The "all-in-one" system addresses major pathological factors associated with diabetic wounds in a single platform, with potential applications for other challenging wound types.

A Multidimensional Approach to Modulating Ionizable Lipids for High-Performing and Organ-Selective mRNA Delivery.

The development of lipid nanoparticles (LNPs) has enabled a successful clinical application of mRNA vaccines. However, disclosure of design principles for the core component-ionizable lipids (ILs), improving the delivery efficacy and organ targeting of LNPs, remains a formidable challenge. Herein, we report a powerful strategy to modulate ILs in one-step chemistry using the Ugi four-component reaction (Ugi-4CR) under mild conditions. A large IL library of new structures was established simply and efficiently through a multidimensional approach, allowing us to identify the top-performing ILs in delivering mRNA via the formulated LNPs. Adjusting the skeleton of ILs has transformed the organ-specific and robust transfection in mRNA delivery from the liver to the spleen following different administration routes. Of note, a series of isomeric ILs were prepared and we found that the isomers mattered greatly in the performance of LNPs for mRNA delivery. Furthermore, owing to the bis-amide bonds formed in the Ugi-4CR reaction, the ILs within LNPs may form hydrogen bonding intermolecularly, facilitating the colloidal stabilization of LNPs. This work provides clues to the rapid discovery and rational design of IL candidates, assisting the application of mRNA therapeutics.

Direct Cytosolic Delivery of Proteins and CRISPR-Cas9 Genome Editing by Gemini Amphiphiles via Non-Endocytic Translocation Pathways.

Intracellular delivery of therapeutic biomacromolecules is often challenged by the poor transmembrane and limited endosomal escape. Here, we establish a combinatorial library composed of 150 molecular weight-defined gemini amphiphiles (GAs) to identify the vehicles that facilitate robust cytosolic delivery of proteins in vitro and in vivo. These GAs display similar skeletal structures but differential amphiphilicity by adjusting the length of alkyl tails, type of ionizable cationic heads, and hydrophobicity or hydrophilicity of a spacer. The top candidate is highly efficient in translocating a broad spectrum of proteins with various molecular weights and isoelectric points into the cytosol. Particularly, we notice that the entry mechanism is predominantly mediated via the lipid raft-dependent membrane fusion, bypassing the classical endocytic pathway that limits the cytosolic delivery efficiency of many presently available carriers. Remarkably, the top GA candidate is capable of delivering hard-to-deliver Cas9 ribonucleoprotein in vivo, disrupting KRAS mutation in the tumor-bearing mice to inhibit tumor growth and extend their survival. Our study reveals a GA-based small-molecule carrier platform for the direct cytosolic delivery of various types of proteins for therapeutic purposes.

Exploring the Effect of Amphiphile Architecture on Intracellular Protein Delivery Capacity: Dimeric versus Trimeric Amphiphiles.

Carrier-mediated intracellular protein delivery holds tremendous application potential in biology and medicine. The ideal carrier should be well-controlled and cost-effective and able to facilitate robust delivery of diverse types of proteins into the target cells, thus ensuring efficacy in different application scenarios. Here, we describe a modular chemistry approach for generating a small-molecule amphiphile molecular library based on the Ugi four-component reaction under one-pot and mild conditions. Then, two different types of amphiphiles with the dimeric or trimeric architecture were obtained for intracellular protein delivery through in vitro screening test. Depending on the precise adjustment of the hydrophobic tails of amphiphiles, the optimized trimeric amphiphile (TA) exhibited more superior protein loading performance and a higher efficiency of delivering proteins into cells through the endocytosis pathway and subsequent endosomal escape. Furthermore, we demonstrated that the TA could be a universal delivery carrier capable of transporting broad-spectrum proteins, especially for the hard-to-deliver native antibodies, into the cytosol. Overall, we describe a robust amphiphile platform with a well-defined and cost-effective design to improve the cytosolic protein delivery capacity, exhibiting great promise for developing intracellular protein-based therapeutics.

Dynamic Stimulations with Bioengineered Extracellular Matrix-Mimicking Hydrogels for Mechano Cell Reprogramming and Therapy.

Cells interact with their surrounding environment through a combination of static and dynamic mechanical signals that vary over stimulus types, intensity, space, and time. Compared to static mechanical signals such as stiffness, porosity, and topography, the current understanding on the effects of dynamic mechanical stimulations on cells remains limited, attributing to a lack of access to devices, the complexity of experimental set-up, and data interpretation. Yet, in the pursuit of emerging translational applications (e.g., cell manufacturing for clinical treatment), it is crucial to understand how cells respond to a variety of dynamic forces that are omnipresent in vivo so that they can be exploited to enhance manufacturing and therapeutic outcomes. With a rising appreciation of the extracellular matrix (ECM) as a key regulator of biofunctions, researchers have bioengineered a suite of ECM-mimicking hydrogels, which can be fine-tuned with spatiotemporal mechanical cues to model complex static and dynamic mechanical profiles. This review first discusses how mechanical stimuli may impact different cellular components and the various mechanobiology pathways involved. Then, how hydrogels can be designed to incorporate static and dynamic mechanical parameters to influence cell behaviors are described. The Scopus database is also used to analyze the relative strength in evidence, ranging from strong to weak, based on number of published literatures, associated citations, and treatment significance. Additionally, the impacts of static and dynamic mechanical stimulations on clinically relevant cell types including mesenchymal stem cells, fibroblasts, and immune cells, are evaluated. The aim is to draw attention to the paucity of studies on the effects of dynamic mechanical stimuli on cells, as well as to highlight the potential of using a cocktail of various types and intensities of mechanical stimulations to influence cell fates (similar to the concept of biochemical cocktail to direct cell fate). It is envisioned that this progress report will inspire more exciting translational development of mechanoresponsive hydrogels for biomedical applications.

Mechano-responsive hydrogel for direct stem cell manufacturing to therapy.

Bone marrow-derived mesenchymal stem cell (MSC) is one of the most actively studied cell types due to its regenerative potential and immunomodulatory properties. Conventional cell expansion methods using 2D tissue culture plates and 2.5D microcarriers in bioreactors can generate large cell numbers, but they compromise stem cell potency and lack mechanical preconditioning to prepare MSC for physiological loading expected in vivo. To overcome these challenges, in this work, we describe a 3D dynamic hydrogel using magneto-stimulation for direct MSC manufacturing to therapy. With our technology, we found that dynamic mechanical stimulation (DMS) enhanced matrix-integrin ß1 interactions which induced MSCs spreading and proliferation. In addition, DMS could modulate MSC biofunctions including directing MSC differentiation into specific lineages and boosting paracrine activities (e.g., growth factor secretion) through YAP nuclear localization and FAK-ERK pathway. With our magnetic hydrogel, complex procedures from MSC manufacturing to final clinical use, can be integrated into one single platform, and we believe this 'all-in-one' technology could offer a paradigm shift to existing standards in MSC therapy.

Nanoadjuvants Actively targeting lymph node conduits and blocking tumor invasion in lymphatic vessels.

Great efforts have been made to manipulate nanoparticles (NPs) with a diameter of 10-100 nm to passively target lymph nodes (LNs) to magnitude anti-tumor activity of T cells. However, no attention has been paid to increasing the retention of NPs with active affinity in order to induce a prolonged release of antigens or molecular adjuvants in the LNs mattering the immune response. Here, we formulated two NPs encapsulated with imiquimod (IMQ), a TLR7/8 agonist, and paclitaxel (PTX) and further modified them with tannic acid (TA), respectively, to generate IMQ NP and PTX NP with a final diameter of approximately 40 nm. Attributing a strong affinity of TA molecules to the elastin of LN conduits, the TA modified IMQ NPs can bypass the gaps in the layer of lymphatic endothelial cells and enter the paracortex through the lymph node capsule-associated (LNC) conduits. Similarly, the TA modified PTX NPs increased delivery of PTX to the metastatic tumor site in LNs, where the tumor-associated antigens were released and presented by conduits-lining dendritic cells to activate T cells. Thus, the NPs with deposition to LN conduits showed excellent performance in preventing lymphovascular invasion of triple-negative breast cancer cells and lung metastasis thereafter. On the contrary, the NPs without TA flowed through the subcutaneous sinus existing LNs directly by efferent lymphatic vessels showing relatively poor therapeutic outcomes. This study reveals that TA may mediate the long retention of antigens and molecular adjuvants to be delivered to deep LNs for developing potent vaccination technology.

Orally administrable polyphenol-based nanoparticles achieve anti-inflammation and antitumor treatment of colon diseases.

Colorectal cancer is the third most common malignancy that leads to significant mortality around the world. Chronic colonic inflammation could induce a protumor effect by the massive release of pro-inflammatory cytokines, facilitating migration, invasion, and metastasis of malignant cells in colorectal cancer. Therefore, developing a combination regimen of anti-inflammation and antitumor therapies is a promising strategy for the treatment of colorectal cancer. Here, we report that tannic acid-containing nanoparticles, formed by a turbulent-mixing technique, have exhibited uniform size, high stability, and pH-triggered drug release in the gastrointestinal tract, and could overcome intestinal mucosa for drug delivery in the colorectal region. As a drug carrier itself, with potent antioxidant and anti-inflammatory properties, tannic acid-containing nanoparticles showed great therapeutic effect in preventing the development of colitis-associated colorectal cancer (CAC) through oral administration. Furthermore, we used a therapeutic nanocarrier to deliver chemotherapeutic drugs for CAC treatment, generating lower systemic toxicity and superior antitumor performance through concurrent anti-inflammation and antitumor treatment. As a result, we confirmed that the drug carrier itself with therapeutic function could improve the overall therapeutic performance, and provided a safe and effective tannic acid-containing nanoplatform for the prevention and treatment of colon diseases.

Self-degradable poly(ß-amino ester)s promote endosomal escape of antigen and agonist.

Vaccination with subunit nanovaccines is a promising strategy to combat virus infection and tumor development. However, immunogenicity of present nanovaccines is still unsatisfied for clinical translation. Here, we developed a nanovaccine loading a STING agonist, 2'3'-cGAMP and, a model subunit antigen, OVA, by using a well-defined self-degradable poly(ß-amino ester)s to treat B16F10-OVA melanoma tumors. The polymer underwent slow hydrolysis at pH 5.5 but self-degraded induced by the amino groups along the polyester chain at pH > 6.5. It is shown that the self-degradation products facilitated the release of 2'3'-cGAMP and OVA from early endolysome to the cytosol, where the two components strongly activated CD8+ T lymphocytes (CTLs) and significantly enhanced Ifn1, TNF, Cxcl9, and Cxcl10 expression. In turn, the tumor microenvironment was remolded from cold to hot. Moreover, the nanovaccine could be quickly drained to sentinel lymph nodes after intratumoral injection. The nanovaccine with strong immunogenicity also could reduce the side effects of systemic inflammatory reaction caused by molecular 2'3'-cGAMP. The tumor progression of animals was inhibited, and their survival rates increased significantly. Thus, the multifunctional biodegradable material provided a new delivery system for a cancer vaccine to translate to clinics.

Antioxidant Enzymes Sequestered within Lipid-Polymer Hybrid Nanoparticles for the Local Treatment of Inflammatory Bowel Disease.

The local treatment of inflammatory bowel disease (IBD) by enzyme therapeutics is challenging owing to hostile environments in the gastrointestinal tract, leading to the hydrolysis and enzymatic degradation of labile proteins. In this study, safe and efficient local drug delivery systems were developed by antioxidant superoxide dismutase (SOD) sequestered within lipid-polymer hybrid nanoparticles through sequential self-assembly processes. Interestingly, we found that the sequestered SOD exhibited long-term enzymatic stability and comparable biological activity to the enzymes in the native form, probably owing to particle encapsulation providing a physical barrier to prevent the enzymolysis of proteins. We demonstrated that nanoparticle-based local drug delivery systems showed excellent mucus-penetrating ability and inflammation-targeting properties, owing to the particle surface with a poly(ethylene glycol) (PEG) coating and folate functionalization, thus improving mucosal retention time and drug delivery efficiency within the colorectal region. Furthermore, SOD-containing lipid-polymer hybrid nanoparticles could effectively mitigate inflammatory responses by regulating the secretion of inflammation-associated cytokines, thus increasing therapeutic outcomes in colitis mice through intrarectal administration. The findings indicated that antioxidant enzymes sequestered within lipid-polymer hybrid nanoparticles might be potential enzyme therapeutics for the local treatment of some inflammatory diseases in the near future.

Therapeutic Delivery to the Brain via the Lymphatic Vasculature.

Targeted delivery of therapeutics to disease sites has been one of the biggest challenges in medicine, as it determines the treatment efficacy of virtually all chemical and biological drugs. Furthermore, it is particularly difficult to achieve for diseases in the brain because of an additional barrier compared to other organs, the blood-brain barrier (BBB). Here, we report a new mechanism for drug delivery to the brain, nanoparticle-mediated transport through the newly discovered brain lymphatic vasculatures, bypassing the BBB and other issues associated with conventional intravenous (i.v.) administration. Using indocyanine green (ICG)-loaded PLGA nanoparticles as a model, we show that drug uptake in the brain by subcutaneous (s.c.) injection at the neck near a local lymph node is 44-fold higher than the i.v. route, resulting in effective treatment of glioblastoma in mice by photodynamic therapy. These findings will open a new paradigm for the treatment of a variety of diseases in the brain.

Therapeutic nanovaccines sensitize EBV-associated tumors to checkpoint blockade therapy.

For successful treatment of EBV-associated tumors immune tolerance must be broken. While most studies of EBV-associated tumor vaccines have focused on augmenting tumor-specific effector T cells, the effects of these vaccines on the immune-suppressive tumor microenvironment have not been investigated. Here, we describe the manufacture of a nanovaccine using tannic acid (TA) and a newly constructed protein antigen for EBV-associated tumors with interferon-α (IFN-α) or CpG as adjuvants. TA as a biocompatible material from plant self-assembles with antigens and adjuvants via hydrogen bonding to form well-defined nanoparticulate vaccines by flash nanocomplexation, a scalable yet controllable technique. By targeting lymph nodes, the nanovaccine co-loaded with CpG adjuvant induces strong immune activation and exhibits efficient inhibition tumorigenesis. Moreover, the nanovaccine combining with anti-PD-L1 results a marked decrease in tumor size and prolonged survival of tumor-bearing mice by decreasing infiltration of regulatory T cells to the tumor lesion. This suggests that the nanovaccine can reverse immune checkpoint inhibitor resistance by remodeling the tumor microenvironment. Thus, this study shows a promising strategy for treatment of EBV-positive tumors in patients.

Flash Fabrication of Orally Targeted Nanocomplexes for Improved Transport of Salmon Calcitonin across the Intestine.

Salmon calcitonin (sCT) is a potent calcium-regulating peptide hormone and widely applied for the treatment of some bone diseases clinically. However, the therapeutic usefulness of sCT is hindered by the frequent injection required, owing to its short plasma half-life and therapeutic need for a high dose. Oral delivery is a popular modality of administration for patients because of its convenience to self-administration and high patient compliance, while orally administered sCT remains a great challenge currently due to the existence of multiple barriers in the gastrointestinal (GI) tract. Here, we introduced an orally targeted delivery system to increase the transport of sCT across the intestine through both the paracellular permeation route and the bile acid pathway. In this system, sCT-based glycol chitosan-taurocholic acid conjugate (GC-T)/dextran sulfate (DS) ternary nanocomplexes (NC-T) were produced by a flash nanocomplexation (FNC) process in a kinetically controlled mode. The optimized NC-T exhibited well-controlled properties with a uniform and sub-60 nm hydrodynamic diameter, high batch-to-batch reproducibility, good physical or chemical stability, as well as sustained drug release behaviors. The studies revealed that NC-T could effectively improve the intestinal uptake and permeability, owing to its surface functionalization with the taurocholic acid ligand. In the rat model, orally administered NC-T showed an obvious hypocalcemia effect and a relative oral bioavailability of 10.9%. An in vivo assay also demonstrated that NC-T induced no observable side effect after long-term oral administration. As a result, the orally targeted nanocomplex might be a promising candidate for improving the oral transport of therapeutic peptides.

Augmenting Therapeutic Potential of Polyphenols by Hydrogen-Bonding Complexation for the Treatment of Acute Lung Inflammation.

Dysregulated inflammation is considered as an essential pathological process in inflammation-associated diseases, which would be aggravated by high levels of reactive oxygen species (ROS) generation inducing oxidative stress. Currently, extensive attention has been paid to polyphenolic compounds owing to their broad spectrum biological activities, such as antioxidant and anti-inflammatory effects, while their therapeutic potential has been compromised by the poor stability, short plasma half-life, and low bioavailability. Given that polyphenols have a wide range of structural characteristics and various physicochemical properties, there remains a real challenge toward green, mass production of universal nanocarriers for effective entrapment of these active pharmaceutical ingredients. In this study, we adopted a flash nanocomplexation (FNC) platform to prepare nanocomplexes comprising polyphenols and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) enabled by hydrogen bonding. We confirmed that the molecular structure of polyphenols has a great influence on their complexation with TPGS, and stable nanocomplexes were formed when the number of phenolic hydroxyl groups of polyphenols was above the value of 8. These hydrogen-bonded nanocomplexes produced by an FNC apparatus exhibited well-controlled quality with uniform size, good colloidal stability, and high batch-to-batch repeatability, thus improving the druggability as potent nanotherapeutics for antioxidant and anti-inflammatory applications. In vivo experiments indicated that the optimal nanocomplex (EGCG-NC) can be applied to ameliorate acute lung injury in a mice model after nasal administration. These results proved that polyphenols formulated with TPGS for nanocomplex formation through hydrogen-bonding complexation could augment their therapeutic potential for modulating hyperactive inflammation in the treatment of acute lung inflammation.

A versatile supramolecular nanoadjuvant that activates NF-κB for cancer immunotherapy.

Although powerful adjuvants hold promise of vaccines for cancer immunotherapy, cumbersome preparation processes, elusive mechanisms and failure to induce T cell responses have largely limited their clinical translation. Due to their ease of synthesis, good biocompatibility and designable bioactivity, peptide derivatives-based supramolecular nanomaterials have attracted increasing interest in improving the immunogenicity of cancer vaccines. Methods: Herein, we synthesized an NF-κB-activating supramolecular nanoadjuvant (3DSNA) that is prepared by pH-triggering self-assembly of a positively charged D-configurational peptide derivative. The immunostimulatory activity of 3DNSA was explored in vitro and in vivo. Results: 3DSNA can strongly absorb the model antigen (ovalbumin, OVA) through electrostatic interaction. Then, 3DSNA promotes ingestion and cross-presentation of OVA, upregulation of costimulatory factors (CD80 and CD86) and secretion of proinflammatory cytokines (IL-6 and IL-12) by dendritic cells (DCs), accompanied by activation of the innate immune response (NF-κB signaling), resulting in long-term antigen-specific memory and effector CD8+ T cells response. When compared with conventional aluminum hydroxide adjuvant and the corresponding L-configurational supramolecular nanoadjuvant (3LSNA), 3DSNA-adjuvanted OVA (3DSNA+OVA) significantly prevents oncogenesis in naïve mice with a complete response rate of 60 %, restrains the tumor growth and prolongs the survival of melanoma-bearing mice. Conclusion: These findings demonstrate that 3DSNA is a promising neo-adjuvant that enables various vaccines to be therapeutic for many important diseases including cancer.

Scalable fabrication of metal-phenolic nanoparticles by coordination-driven flash nanocomplexation for cancer theranostics.

Although various nanomaterials have been developed for cancer theranostics, there remains a key challenge for effective integration of therapeutic drugs and diagnostic agents into a single multicomponent nanoparticle via a simple and scalable approach. Moreover, the bottlenecks of nanoformulation in composition controllability, colloidal stability, drug loading capability and batch-to-batch repeatability currently still hinder the clinical translation of nanomedicine. Herein, we report a coordination-driven flash nanocomplexation (cFNC) process to achieve scalable fabrication of doxorubicin-based metal-phenolic nanoparticles (DITH) with a hyaluronic acid surface layer through efficient control of coordination reaction kinetics in a rapid turbulent mixing. The optimized DITH exhibited a small hydrodynamic diameter (84 nm), narrow size distribution, high drug loading capacity (26.6%), high reproducibility and pH-triggered drug release behaviors. The studies indicated that DITH significantly increased cellular endocytosis mediated by CD44+ receptor targeting and accelerated intracellular drug release owing to the sensitivity of DITH to environmental pH stimuli. Furthermore, guided by T1-weighted magnetic resonance (MR) imaging function endowed by ferric ions, DITH exhibited prolonged blood circulation, enhanced tumor accumulation, improved therapeutic performance and decreased toxic side effects after intravenous injection in a MCF-7 tumor-bearing mice model. These results confirmed that the developed DITH is a promising vehicle for cancer theranostic applications, and our work provided a new strategy to promote the development of translational nanomedicine.

Scalable Manufacturing of Enteric Encapsulation Systems for Site-Specific Oral Insulin Delivery.

Oral drug delivery is a more favored mode of administration because of its ease of administration, high patient compliance, and low healthcare costs. However, no oral protein formulations are commercially available currently due to hostile gastrointestinal (GI) barriers resulting in insignificant oral bioavailability of macromolecular drugs. Herein, we used insulin as a model protein drug; insulin-loaded N-(2-hydroxy)-propyl-3-trimethylammonium chloride modified chitosan (HTCC)/sodium tripolyphosphate (TPP) nanocomplex (NC) as a nanocore was further encapsulated into enteric Eudragit L100-55 material, through a two-step flash nanocomplexation (FNC) process in a reliable and scalable manner, forming our NC-in-Eudragit composite particles (NE). Particle size and surface properties of our optimized NE were tailored to protect the loaded insulin from acidic degradation in the hostile stomach environment and to achieve intestinal site-specific drug release as well as the improvement of oral delivery efficiency of insulin. In addition, the oral administration of the optimized NE to type 1 diabetic rats could induce a very significant hypoglycemic effect with a relative oral bioavailability of 13.3%. Our results demonstrated that enteric encapsulation of nanotherapeutics using a FNC apparatus could cause drug formulations to possess better size controllability, batch-mode reproducibility, and homogeneous surface coating and then significantly enhance their oral bioavailability of insulin, indicating its great potential for clinical translation of oral protein therapeutics.

Hydrogen-Bonded Tannic Acid-Based Anticancer Nanoparticle for Enhancement of Oral Chemotherapy.

Oral chemotherapy has been emerging as a hopeful therapeutic regimen for the treatment of various cancers because of its high safety and convenience, lower costs, and high patient compliance. Currently, nanoparticulate drug delivery systems (NDDS) exhibit many unique advantages in mediating oral drug delivery; however, many anticancer drugs that were susceptible in hostile gastrointestinal (GI) environment showed poor permeability across intestinal epithelium, and most materials used as drug carriers are nonactive excipients and displayed no therapeutically relevant function, which leads to low oral bioavailability and therapeutic efficacy of anticancer drugs (e.g., paclitaxel). Inspired by these, in this study, paclitaxel (PTX) was used as a model drug, depending on intermolecular hydrogen-bonded interactions, PTX-loaded tannic acid/poly( N-vinylpyrrolidone) nanoparticles (PTX-NP) were produced by a flash nanoprecipitation (FNP) process. The optimized PTX-NP showed an average diameter of 54 nm with a drug encapsulation efficiency of 80% and loading capacity of 14.5%. Molecular dynamics simulations were carried out to illuminate the assembling mechanism of hydrogen-bonded PTX-NP. In vitro and in vivo results confirmed that PTX-NP showed pH-dependent intestinal site-specific drug release, P-gp inhibitory function by tannic acid (TA), prolonged intestinal retention, and improved trans-epithelial transport properties. Oral administration of PTX-NP generated a high oral delivery efficiency and relative oral bioavailability of 25.6% in rats, and further displayed a significant tumor-inhibition effect in a xenograft breast tumor model. These findings confirmed that our PTX-NP might be a promising oral drug formulation for chemotherapy.