A biomimetic nanocarrier facilitates glucose consumption and reactive oxide species accumulation in enzyme therapy for colorectal cancer.

Glucose oxidase (GOx)-based enzyme therapeutics are potential alternatives for colorectal cancer (CRC) treatment via glucose consumption and accumulation of hydrogen peroxide (H2O2). Given that H2O2 can be eliminated by cytoprotective autophagy, autophagy inhibitors that can interrupt autolysosome-induced H2O2 elimination are promising combination drugs of GOx. Here, we developed a multifunctional biomimetic nanocarrier for effective co-delivery of an autophagy inhibitor-chloroquine phosphate (CQP) and GOx to exert their synergistic effect by irreversibly upregulating intracellular reactive oxygen species (ROS) levels. Poly (D, l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were used to encapsulate both GOx and CQP using a W/O/W multi-emulsion method. Calcium phosphate (CaP) was used to "fix" CQP to GOx in the internal water phase, where it served as a pH-sensitive unit to facilitate intracellular drug release. Folic acid-modified red blood cell membranes (FR) were used to camouflage the GOx/CQP/CaP encapsulated PLGA NPs (referred to as PLGA/GCC@FR). In an AOM/DSS-induced CRC mouse model, PLGA/GCC@FR exhibited improved antitumor effects, in which the number of tumor nodes were only a quarter of that in the free drug combination group. The enhanced therapeutic effects of PLGA/GCC@FR were attributed to the prolonged tumor retention which was verified by both dynamic in vivo imaging and drug biodistribution. This multifunctional biomimetic nanocarrier facilitated combined enzyme therapeutics by depleting glucose and augmenting intracellular ROS levels in tumor cells, which exerted a synergistic inhibitory effect on tumor growth. Therefore, this study proposed a novel strategy for the enhancement of combined enzyme therapeutics, which provided a promising method for effective CRC treatment.

Effect of folic acid-linked chitosan-coated PLGA-based curcumin nanoparticles on the redox system of glioblastoma cancer cells.

OBJECTIVES: Oxidative stress is one of the carcinogenic mechanisms underlying the development of glioblastoma multiforme (GBM), a highly aggressive brain tumor type associated with poor prognosis. Curcumin is known to be an efficient antioxidant, anti-inflammatory, and anticancer compound. However, its poor solubility in water, inappropriate pharmacokinetics, and low bioavailability limit its use as an antitumor drug. We prepared PLGA-based curcumin nanoparticles changed with folic acid and chitosan (curcumin-PLGA-CS-FA) and evaluated its effects on GBM tumor cells' redox status. METHODS: The nanoprecipitation method was used to synthesize CU nanoparticles (CU-NPs). The size, morphology, and stability were characterized by DLS, SEM, and zeta potential analysis, respectively. The CU-NPs' toxic properties were studied by MTT assay and measuring the intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) concentrations. The study was completed by measuring the gene expression levels and activity of superoxide dismutase, catalase, glutaredoxin, and thioredoxin antioxidant enzymes. RESULTS: The size, polydispersity index, and zeta potential of CU-NPs were 77.27 nm, 0.29, and -22.45 mV, respectively. The encapsulation efficiency was approximately 98%. Intracellular ROS and MDA levels decreased after CU-NP treatment. Meanwhile, the CU-NPs increased gene expression and activity of superoxide dismutase, catalase, glutaredoxin, and thioredoxin antioxidant enzymes. CONCLUSION: CU-NPs might be effective in the prevention and treatment of glioblastoma cancer by modulating the antioxidant-oxidant balance.

Targeted Delivery of Anticancer Drug Loaded Charged PLGA Polymeric Nanoparticles Using Electrostatic Field.

Pure positive electrostatic charges (PPECs) show suppressive effect on the proliferation and metabolism of invasive cancer cells without affecting normal tissues. PPECs are used for the delivery of drug-loaded polymeric nanoparticles (DLNs) capped with negatively charged poly(lactide-co-glycolide) (PLGA) and Poly(vinyl-alcohol) PVA into the tumor site of mouse models. The charged patch is installed on top of the skin in the mouse models' tumor region, and the controlled selective release of the drug is assayed by biochemical, radiological, and histological experiments on both tumorized models and normal rats' livers. It is found that DLNs synthesized by PLGA show great attraction to PPECs due to their stable negative charges, which would not degrade immediately in blood. The burst and drug release after less than 48h of this synthesized DLNs are 10% and 50%, respectively. These compounds can deliver the loaded-drug into the tumor site with the assistance of PPECs, and the targeted-retarded release will take place. Hence, local therapy can be achieved with much lower drug concentration (conventional chemotherapy [2 mg kg-1 ] versus DLNs-based chemotherapy [0.75 mg kg-1 ]) with negligible side effects in non-targeted organs. PPECs have many potential clinical applications for advanced-targeted chemotherapy with the lowest discernible side effects.

Ultrasound Responsive Nanovaccine Armed with Engineered Cancer Cell Membrane and RNA to Prevent Foreseeable Metastasis.

Cancer vaccine has been considered as a promising immunotherapy by inducing specific anti-tumor immune response. Rational vaccination at suitable time to efficiently present tumor associated antigen will boost tumor immunity and is badly needed. Here, a poly (lactic-co-glycolic acid) (PLGA)-based cancer vaccine of nanoscale is designed, in which engineered tumor cell membrane proteins, mRNAs, and sonosensitizer chlorin e6 (Ce6) are encapsulated at high efficiency. The nanosized vaccine can be efficiently delivered into antigen presentation cells (APCs) in lymph nodes after subcutaneous injection. In the APCs, the encapsulated cell membrane and RNA from engineered cells, which have disturbed splicing resembling the metastatic cells, provide neoantigens of metastatic cancer in advance. Moreover, the sonosensitizer Ce6 together with ultrasound irradiation promotes mRNA escape from endosome, and augments antigen presentation. Through 4T1 syngeneic mouse model, it has been proved that the proposed nanovaccine is efficient to elicit antitumor immunity and thus prevent cancer metastasis.

A novel combination for the treatment of small cell lung cancer: Active targeted irinotecan and stattic co-loaded PLGA nanoparticles.

Polymeric nanoparticles are widely used drug delivery systems for cancer treatment due to their properties such as ease of passing through biological membranes, opportunity to modify drug release, specifically targeting drugs to diseased areas, and potential of reducing side effects. Here, we formulated irinotecan and Stattic co-loaded PLGA nanoparticles targeted to small cell lung cancer. Nanoparticles were successfully conjugated with CD56 antibody with a conjugation efficiency of 84.39 ± 1.01%, and characterization of formulated nanoparticles was conducted with in-vitro and in-vivo studies. Formulated particles had sizes in the range of 130-180 nm with PDI values smaller than 0.3. Encapsulation and active targeting of irinotecan and Stattic resulted in increased cytotoxicity and anti-cancer efficiency in-vitro. Furthermore, it was shown with ex-vivo biodistribution studies that conjugated nanoparticles were successfully targeted to CD56-expressing SCLC cells and distributed mainly to tumor tissue and lungs. Compliant with our hypothesis and literature, the STAT3 pathway was successfully inhibited with Stattic solution and Stattic loaded nanoparticles. Additionally, intravenous injection of conjugated co-loaded nanoparticles resulted in decreased side effects and better anti-tumor activity than individual solutions of drugs in SCLC tumor-bearing mice. These results may indicate a new treatment option for clinically aggressive small cell lung cancer.

Tumor-Antigen Activated Dendritic Cell Membrane-Coated Biomimetic Nanoparticles with Orchestrating Immune Responses Promote Therapeutic Efficacy against Glioma.

Immunotherapy has had a profound positive effect on certain types of cancer but has not improved the outcomes of glioma because of the blood-brain barrier (BBB) and immunosuppressive tumor microenvironment. In this study, we developed an activated mature dendritic cell membrane (aDCM)-coated nanoplatform, rapamycin (RAPA)-loaded poly(lactic-co-glycolic acid) (PLGA), named aDCM@PLGA/RAPA, which is a simple, efficient, and individualized strategy to cross the BBB and improve the immune microenvironment precisely. In vitro cells uptake and the transwell BBB model revealed that the aDCM@PLGA/RAPA can enhance homotypic-targeting and BBB-crossing efficiently. According to the in vitro and in vivo immune response efficacy of aDCM@PLGA/RAPA, the immature dendritic cells (DCs) could be stimulated into the matured status, which leads to further activation of immune cells, such as tumor-infiltrating T cells and natural killer cells, and can induce the subsequent immune responses through direct and indirect way. The aDCM@PLGA/RAPA treatment can not only inhibit glioma growth significantly but also has favorable potential ability to induce glial differentiation in the orthotopic glioma. Moreover, the aDCM@PLGA could induce a robust CD8+ effector and therefore suppress orthotopic glioma growth in a prophylactic setup, which indicates certain tumor immunity. Overall, our work provides an effective antiglioma drug delivery system which has great potential for tumor combination immunotherapy.

The amount of dextran in PLGA nanocarriers modulates protein corona and promotes cell membrane damage.

Polymeric nanocarriers (NCs) are efficient vehicles to prevent drug unspecific biodistribution and increase the drug amounts delivered to tumor tissues. However, some toxicological aspects of NCs still lack a comprehensive assessment, such as their effects on cellular processes that lead to toxicity. We evaluate the interaction of poly(lactic-co-glycolic acid) (PLGA) NCs prepared using dextran (Dex) and Pluronic®-F127 as stabilizing agents with myocardial cells (H9C2), breast adenocarcinoma cells (MCF-7) and macrophages (RAW 264.7) to address the effect of Dex in PLGA NC formulations. By an emulsion diffusion method, doxorubicin-loaded NCs were prepared with no Dex (PLGA-DOX), 1% (w/v) Dex (Dex1/PLGA-DOX) and 5% (w/v) Dex (Dex5/PLGA-DOX). Uptake analyses revealed a significant reduction in Dex5/PLGA-DOX NC uptake by H9C2 and MCF-7, as in the case of Dex1/PLGA-DOX NCs in the absence of in vitro protein corona, revealing an effect of dextran concentration on the formation of protein corona. RAW 264.7 cells presented a greater uptake of Dex5/PLGA-DOX NCs than the other NCs likely because of receptor mediated endocytosis, since C-type lectins like SIGN-R1, mannose receptors and scavenger receptor type 1 that are expressed in RAW 264.7 can mediate Dex uptake. Despite the lower uptake, Dex5/PLGA-DOX NCs promote the generation of reactive oxygen species and oxidative membrane damage in MCF-7 and H9C2 even though cellular metabolic activity assessed by MTT was comparable among all the NCs. Our results highlight the importance of an in-depth investigation of the NC-cell interaction considering additional mechanisms of damage apart from metabolic variations, as nanoparticle-induced damage is not limited to imbalance in metabolic processes, but also associated with other mechanisms, e.g., membrane and DNA damage.

'Mito-Bomb': a novel mitochondria-targeting nanosystem for ferroptosis-boosted sonodynamic antitumor therapy.

Mitochondria play an important role in regulating tumor cell death and metabolism so that they can be potential therapeutic targets. Sonodynamic therapy (SDT) represents an attractive antitumor method that induces apoptosis by producing highly toxic reactive oxygen species (ROS). Mitochondria-targeting SDT can cause oxidative damage and improve the efficiency of tumor therapy. However, due to the nonselective distribution of nanosystems and the anti-apoptotic mechanism of cancer cells, the therapeutic effect of SDT is not ideal. Therefore, we proposed a novel mitochondria-targeting nanosystem ('Mito-Bomb') for ferroptosis-boosted SDT. Sonosensitizer IR780 and ferroptosis activator RSL-3 were both encapsulated in biocompatible poly(lactic-co-glycolic acid) (PLGA) nanoparticles to form 'Mito-Bomb' (named IRP NPs). IR780 in this nanosystem was used to mediate mitochondria-targeting SDT. RSL-3 inhibited the activity of GPX4 in the antioxidant system to induce ferroptosis of tumor cells, which could rewire tumor metabolism and make tumor cells extremely sensitive to SDT-induced apoptosis. Notably, we also found that RSL-3 can inhibit hypoxia inducible factor-1α (HIF-1α) and induce ROS production to improve the efficacy of SDT to synergistically antitumor. RSL-3 was applied as a 'One-Stone-Three-Birds' agent for cooperatively enhanced SDT against triple-negative breast cancer. This study presented the first example of RSL-3 boosting mitochondria-targeting SDT as a ferroptosis activator. The 'Mito-Bomb' biocompatible nanosystem was expected to become an innovative tumor treatment method and clinical transformation.

Hydrogel-Embedded Poly(Lactic-co-Glycolic Acid) Microspheres for the Delivery of hMSC-Derived Exosomes to Promote Bioactive Annulus Fibrosus Repair.

OBJECTIVE: Intervertebral disk degeneration is a prevalent postoperative complication after discectomy, underscoring the need to develop preventative and bioactive treatment strategies that decelerate degeneration and seal annulus fibrosus (AF) defects. Human mesenchymal stem cell-derived exosomes (MSC-Exos) hold promise for cell-free bioactive repair; however, their ability to promote AF repair is poorly understood. The objective of this study was to evaluate the ability of MSC-Exos to promote endogenous AF repair processes and integrate MSC-Exos within a biomaterial delivery system. DESIGN: We characterize biophysical and biochemical properties of normoxic (Nx) and hypoxic (Hx) preconditioned MSC-Exos from young, healthy donors and examine their effects on AF cell proliferation, migration, and gene expression. We then integrate a poly(lactic-co-glycolic acid) microsphere (PLGA µSphere) delivery platform within an interpenetrating network hydrogel to facilitate sustained MSC-Exo delivery. RESULTS: Hx MSC-Exos led to a more robust response in AF cell proliferation and migration than Nx MSC-Exos and was selected for a downstream protection experiment. Hx MSC-Exos maintained a healthy AF cell phenotype under a TNFα challenge in vitro and attenuated catabolic responses. In all functional assays, AF cell responses were more sensitive to Hx MSC-Exos than Nx MSC-Exos. PLGA µSpheres released MSC-Exos over a clinically relevant timescale without affecting hydrogel modulus or pH upon initial embedment and µSphere degradation. CONCLUSIONS: This MSC-Exo treatment strategy may offer benefits of stem cell therapy without the need for exogenous stem cell transplantation by stimulating cell proliferation, promoting cell migration, and protecting cells from the degenerative proinflammatory microenvironment.

Versatile Nano-PROTAC-Induced Epigenetic Reader Degradation for Efficient Lung Cancer Therapy.

Recent evidence has indicated that overexpression of the epigenetic reader bromodomain-containing protein 4 (BRD4) contributes to a poor prognosis of lung cancers, and the suppression of its expression promotes cell apoptosis and leads to tumor shrinkage. Proteolysis targeting chimera (PROTAC) has recently emerged as a promising therapeutic strategy with the capability to precisely degrade targeted proteins. Herein, a novel style of versatile nano-PROTAC (CREATE (CRV-LLC membrane/DS-PLGA/dBET6)) is developed, which is constructed by using a pH/GSH (glutathione)-responsive polymer (disulfide bond-linked poly(lactic-co-glycolic acid), DS-PLGA) to load BRD4-targeted PROTAC (dBET6), followed by the camouflage with engineered lung cancer cell membranes with dual targeting capability. Notably, CREATE remarkably confers simultaneous targeting ability to lung cancer cells and tumor-associated macrophages (TAMs). The pH/GSH-responsive design improves the release of dBET6 payload from nanoparticles to induce pronounced apoptosis of both cells, which synergistically inhibits tumor growth in both subcutaneous and orthotopic tumor-bearing mouse model. Furthermore, the efficient tumor inhibition is due to the direct elimination of lung cancer cells and TAMs, which remodels the tumor microenvironment. Taken together, the results elucidate the construction of a versatile nano-PROTAC enables to eliminate both lung cancer cells and TAMs, which opens a new avenue for efficient lung cancer therapy via PROTAC.

In vitro and in vivo evaluation of DC-targeting PLGA nanoparticles encapsulating heparanase CD4+ and CD8+ T-cell epitopes for cancer immunotherapy.

Heparanase has been identified as a universal tumor-associated antigen, but heparanase epitope peptides are difficult to recognize. Therefore, it is necessary to explore novel strategies to ensure efficient delivery to antigen-presenting cells. Here, we established a novel immunotherapy model targeting antigens to dendritic cell (DC) receptors using a combination of heparanase CD4+ and CD8+ T-cell epitope peptides to achieve an efficient cytotoxic T-cell response, which was associated with strong activation of DCs. First, pegylated poly(lactic-coglycolic acid) (PLGA) nanoparticles (NPs) were used to encapsulate a combined heparanase CD4+ and CD8+ T-cell epitope alone or in combination with Toll-like receptor 3 and 7 ligands as a model antigen to enhance immunogenicity. The ligands were then targeted to DC cell-surface molecules using a DEC-205 antibody. The binding and internalization of these PLGA NPs and the activation of DCs, the T-cell response and the tumor-killing effect were assessed. The results showed that PLGA NPs encapsulating epitope peptides (mHpa399 + mHpa519) could be targeted to and internalized by DCs more efficiently, stimulating higher levels of IL-12 production, T-cell proliferation and IFN-γ production by T cells in vitro. Moreover, vaccination with DEC-205-targeted PLGA NPs encapsulating combined epitope peptides exhibited higher tumor-killing efficacy both in vitro and in vivo. In conclusion, delivery of PLGA NP vaccines targeting DEC-205 based on heparanase CD4+ and CD8+ T-cell epitopes are suitable immunogens for antitumor immunotherapy and have promising potential for clinical applications.

Immuno-Modulatory Effects of Microparticles Formulated from Degradable Polystyrene Analogue.

Environmental accumulation of non-degradable polystyrene (PS) microparticles from plastic waste poses potential adverse impact on marine life and human health. Herein, microparticles from a degradable PS analogue (dePS) are formulated and their immuno-modulatory characteristics are comprehensively evaluated. Both dePS copolymer and microparticles are chemically degradable under accelerated hydrolytic condition. In vitro studies show that dePS microparticles are non-toxic to three immortalized cell lines. While dePS microparticles do not induce macrophage polarization in vitro, dePS microparticles induce in vivo upregulation of both pro-inflammatory and anti-inflammatory biomarkers in immuno-competent mice, suggesting the coexistence of mixed phenotypes of macrophages in the host immune response to these microparticles. Interestingly, on day 7 following subcutaneous in mice, dePS microparticles induce a lower level of several immuno-modulatory biomarkers (matrix metallo-proteinases (MMPs), tumor necrosis factor (TNF-α), and arginase activity) compared to that of reference poly(lactic-co-glycolic acid) microparticles. Remarkably, compared to PS microparticles, dePS microparticles exhibit similar in vitro and in vivo bioactivity while acquiring additional chemical degradability. Overall, this study gains new insights into the host immune response to dePS microparticles and suggests that this dePS analogue might be explored as an alternative material choice for biomedical and consumer care applications.

N-trimethyl chitosan coated nano-complexes enhance the oral bioavailability and chemotherapeutic effects of gemcitabine.

N-trimethyl chitosan (TMC) is a multifunctional polymer that can be used in various nanoparticle forms in the pharmaceutical, nutraceutical and biomedical fields. In this study, TMC was used as a mucoadhesive adjuvant to enhance the oral bioavailability and hence antitumour effects of gemcitabine formulated into nanocomplexes composed of poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) conjugated with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). A central composite design was applied to achieve the optimal formulation. Cellular uptake and drug transportation studies revealed the nanocomplexes permeate over the intestinal cells via adsorptive-mediated and caveolae-mediated endocytosis. Pharmacokinetic studies demonstrated the oral drug bioavailability of the nanocomplexes was increased 5.1-fold compared with drug solution. In pharmacodynamic studies, the formulation reduced tumour size 3.1-fold compared with the drug solution. The data demonstrates that TMC modified nanocomplexes can enhance gemcitabine oral bioavailability and promote the anticancer efficacy.

Dual-Modality Poly-l-histidine Nanoparticles to Deliver Peptide Nucleic Acids and Paclitaxel for In Vivo Cancer Therapy.

Cationic polymeric nanoformulations have been explored to increase the transfection efficiency of small molecules and nucleic acid-based drugs. However, an excessive positive charge density often leads to severe cell and tissue-based toxicity that restricts the clinical translation of cationic polymeric nanoformulations. Herein, we investigate a series of cationic poly(lactic-co-glycolic acid) (PLGA)-histidine-based nanoformulations for enhanced cytoplasmic delivery with minimal toxicity. PLGA/poly-l-histidine nanoparticles show promising physico-biochemical features and transfection efficiency in a series of in vitro and cell culture-based studies. Further, the use of acetone/dichloromethane as a solvent mixture during the formulation process significantly improves the morphology and size distribution of PLGA/poly-l-histidine nanoparticles. PLGA/poly-l-histidine nanoformulations undergo clathrin-mediated endocytosis. A contrast-matched small-angle neutron scattering experiment confirmed poly-l-histidine's distribution on the PLGA nanoformulations. PLGA/poly-l-histidine formulations containing paclitaxel as a small molecule-based drug and peptide nucleic acids targeting microRNA-155 as nucleic acid analog are efficacious in in vitro and in vivo studies. PLGA/poly-l-histidine NPs significantly decrease tumor growth in PNA-155 (∼6 fold) and paclitaxel (∼6.5 fold) treatment groups in a lymphoma cell line derived xenograft mice model without inducing any toxicity. Hence, PLGA/poly-l-histidine nanoformulations exhibit substantial transfection efficiency and are safe to deliver reagents ranging from small molecules to synthetic nucleic acid analogs and can serve as a novel platform for drug delivery.

Exploring the Toxicity, Lung Distribution, and Cellular Uptake of Rifampicin and Ascorbic Acid-Loaded Alginate Nanoparticles as Therapeutic Treatment of Lung Intracellular Infections.

Nanotechnology is a very promising technological tool to combat health problems associated with the loss of effectiveness of currently used antibiotics. Previously, we developed a formulation consisting of a chitosan and tween 80-decorated alginate nanocarrier that encapsulates rifampicin and the antioxidant ascorbic acid (RIF/ASC), intended for the treatment of respiratory intracellular infections. Here, we investigated the effects of RIF/ASC-loaded NPs on the respiratory mucus and the pulmonary surfactant. In addition, we evaluated their cytotoxicity for lung cells in vitro, and their biodistribution on rat lungs in vivo after their intratracheal administration. Findings herein demonstrated that RIF/ASC-loaded NPs display a favorable lung biocompatibility profile and a uniform distribution throughout lung lobules. RIF/ASC-loaded NPs were mainly uptaken by lung macrophages, their primary target. In summary, findings show that our novel designed RIF/ASC NPs could be a suitable system for antibiotic lung administration with promising perspectives for the treatment of pulmonary intracellular infections.

Enhancing ovarian cancer conventional chemotherapy through the combination with cannabidiol loaded microparticles.

In this work, we evaluated, for the first time, the antitumor effect of cannabidiol (CBD) as monotherapy and in combination with conventional chemotherapeutics in ovarian cancer and developed PLGA-microparticles as CBD carriers to optimize its anticancer activity. Spherical microparticles, with a mean particle size around 25 µm and high entrapment efficiency were obtained. Microparticles elaborated with a CBD:polymer ratio of 10:100 were selected due to the most suitable release profile with a zero-order CBD release (14.13 ± 0.17 µg/day/10 mg Mps) for 40 days. The single administration of this formulation showed an in vitro extended antitumor activity for at least 10 days and an in ovo antitumor efficacy comparable to that of CBD in solution after daily topical administration (≈1.5-fold reduction in tumor growth vs control). The use of CBD in combination with paclitaxel (PTX) was really effective. The best treatment schedule was the pre + co-administration of CBD (10 µM) with PTX. Using this protocol, the single administration of microparticles was even more effective than the daily administration of CBD in solution, achieving a ≈10- and 8- fold reduction in PTX IC50 respectively. This protocol was also effective in ovo. While PTX conducted to a 1.5-fold tumor growth inhibition, its combination with both CBD in solution (daily administered) and 10-Mps (single administration) showed a 2-fold decrease. These results show the promising potential of CBD-Mps administered in combination with PTX for ovarian cancer treatment, since it would allow to reduce the administered dose of this antineoplastic drug maintaining the same efficacy and, as a consequence, reducing PTX adverse effects.

Osteogenic inducer sustained-release system promotes the adhesion, proliferation, and differentiation of osteoblasts on titanium surface.

OBJECTIVE: Biomaterial can be locally applied to promote the osseointegration of dental implants. This study aimed to fabricate an osteogenic inducer (OI) sustained-release system and to evaluate its effects on the adhesion, proliferation, and differentiation of osteoblasts on titanium surfaces. METHODS: First of all, different contents of OI solution were added to the poly (lactic-co-glycolic acid) (PLGA) gel individually to investigate the best physical properties and drug-release rate. Moreover, osteoblasts were isolated from the calvaria of two-month-old New Zealand rabbits through sequential enzymatic digestion. Osteoblasts were seeded onto the surface of Ti disks (control group), Ti coated with PLGA gel (PLGA group), and Ti coated with the OI sustained-release system (PLGA+OI group). Cell adhesion was observed by scanning electron microscopy. Cell proliferation was analyzed by cell counting kit-8. Cell differentiation was tested by alizarin red staining, alkaline phosphatase (ALP) activity and osteogenic-related gene expression. RESULTS: The OI sustained-release system contained 15% OI solution had appropriate physical properties and drug-release rate. The osteoblasts in the PLGA+OI group were in a typical spindle shape with a considerable number indicating the promotion of adhesion and proliferation. The expression of early and late stage osteoblast differentiation genes in the PLGA+OI group were significantly higher than that of the control group and PLGA group at each time point. The PLGA group showed accelerated adhesion and differentiation but reduced proliferation compared with the control. CONCLUSION: The OI sustained-release system promotes the adhesion, proliferation, and differentiation of osteoblasts on titanium surfaces. This system is a cost-effective osteoconductive biomaterial that might be promising for use in dental implantation.

Light-triggered OVA release based on CuS@poly(lactide-co-glycolide acid) nanoparticles for synergistic photothermal-immunotherapy of tumor.

The immunotherapy played a vital role in the treatment of metastatic tumor. To further enhance the effect of the immunotherapy, the combination of photothermal effect can not only eradicate the tumor cells by hyperthermia, but also improved the antigen release in vivo to achieve enhanced immune responses. In this study, a core-shell structured nanocomplex was developed by loading of ovalbumin (OVA) and copper sulfide nanoparticles (CuS-NPs) into the poly(lactide-co-glycolide acid) nanoparticles (PLGA-NPs). The CuS-NPs exhibited favorable photothermal effect, which significantly kill the 4T1 tumor cells in vitro. The photothermal effect of the CuS-NPs accelerated the OVA release, which led to higher levels of IL-6, IL-12 and TNF-α, and activation of CD8+ T cells. Both of the OVA-PLGA-NPs and CuS-NPs with NIR light irradiation contributed inhibited primary tumor while the growth of the distant tumors was not hindered. The irradiated CuS@OVA-PLGA-NPs exhibited a minimal primary tumor because of the combined effect of photothermal therapy and immunotherapy. Moreover, the irradiated CuS@OVA-PLGA-NPs showed the most extensive distribution of CD8+ T cells in the primary and distant tumor, which blocked the rise of the distant tumor. In conclusion, the CuS@OVA-PLGA-NPs presented as a promising strategy for metastatic tumor therapy.

Sustained-release ketamine-loaded nanoparticles fabricated by sequential nanoprecipitation.

Ketamine in sub-anaesthetic doses is an analgesic adjuvant with a morphine-sparing effect. Co-administration of a strong opioid with an analgesic adjuvant such as ketamine is a potential treatment option, especially for patients with cancer-related pain. A limitation of ketamine is its short in vivo elimination half-life. Hence, our aim was to develop biocompatible and biodegradable ketamine-loaded poly(ethylene glycol) (PEG)-block-poly(lactic-co-glycolic acid) (PLGA) nanoparticles for sustained release. Ketamine-encapsulated single polymer PEG-PLGA nanoparticles and double polymer PEG-PLGA/shellac (SH) nanoparticles with a high drug loading of 41.8% (drug weight/the total weight of drug-loaded nanoparticles) were prepared using a new sequential nanoprecipitation method. These drug-loaded nanoparticles exhibited a sustained-release profile for up to 21 days in vitro and for more than 5 days after intravenous injection in mice. Our study demonstrates that high drug loading and a sustained release profile can be achieved with ketamine-loaded PEG-PLGA nanoparticles prepared using this new nanoprecipitation method.

Enzyme-encapsulating polymeric nanoparticles: A potential adjunctive therapy in Pseudomonas aeruginosa biofilm-associated infection treatment.

Pseudomonas aeruginosa is a pathogen known to be associated with a variety of diseases and conditions such as cystic fibrosis, chronic wound infections, and burn wound infections. A novel approach was developed to combat the problem of biofilm antibiotic tolerance by reverting biofilm bacteria back to the planktonic mode of growth. This reversion was achieved through the enzymatic depletion of available pyruvate using pyruvate dehydrogenase, which induced biofilm bacteria to disperse from the surface-associated mode of growth into the surrounding environment. However, direct use of the enzyme in clinical settings is not practical as the enzyme is susceptible to denaturation under various storage conditions. We hypothesize that by encapsulating pyruvate dehydrogenase into degradable, biocompatible poly(lactic-co-glycolic) acid nanoparticles, the activity of the enzyme can be extended to deplete available pyruvate and induce dispersion of mature Pseudomonas aeruginosa biofilms. Several particle formulations were attempted in order to permit the use of the smallest dose of nanoparticles while maintaining pyruvate dehydrogenase activity for an extended time length. The nanoparticles synthesized using the optimal formulation showed an average size of 266.7 ±â€¯1.8 nm. The encapsulation efficiency of pyruvate dehydrogenase was measured at 17.9 ±â€¯1.4%. Most importantly, the optimal formulation dispersed biofilms and exhibited enzymatic activity after being stored at 37 °C for 6 days.