Enhanced anticancer effect of ROS-boosted photothermal therapy by using fucoidan-coated polypyrrole nanoparticles.

Nanomaterial mediated cancer/tumor photo driven hyperthermia has obtained great awareness. Nevertheless, it is a challenge for improving the hyperthermic efficacy lacking resistance to stimulated thermal stress. We thus developed a bioinspired nano-platform utilizing inclusion complexation between photosensitive polypyrrole (Ppy) nanoparticles (NP) and fucoidan (FU). This FU-Ppy NP proved to be an excellent P-selectin-mediated, lung cancer-cell/tumor targeting delivery and specific accumulation, could augment cancer/tumor oxidative stress levels through producing cellular reactive oxygen species. Potent ROS/photothermal combinational therapeutic effects were exhibited by the bioinspired FU-Ppy NP through a selective P-selectin cancer/tumor targeting aptitude for the lung cancer cells/tumor compared with other nano-formulations. The usage of FU-Ppy NP also involves the potential mechanism of suppressing the biological expression of tumor vascular endothelial growth factor (VEGF). This FU biological macromolecule-amplified photothermally therapeutic nano-platform has promising potential for future medical translation in eradicating numerous tumors.

A smart and active film with tunable drug release and color change abilities for detection and inhibition of bacterial growth.

Antimicrobial resistance has become a global issue and thus the development of natural products/biomedical materials composites with antibacterial activities is urgently needed. When acute wounds develop into chronic wounds, the wound environments become alkaline. As long as infections occur, the wound pH further increases, making the wounds difficult to heal. Besides, bacterial growth in poultry, meat, fish and seafood products is usually reflected in a marked increase of pH values. Herein, smart, stimuli responsive self-assembled multilayer and complex film were constructed through the formation of hydrogen bonds and hydrophobic interactions between hydroxypropyl methylcellulose (HPMC) and epigallocatechin-3-gallate (EGCG), thereby greatly reducing the hydrophilicity of HPMC and offering enhanced mechanical strength, superior free radical scavenging capability, and improved water vapor and light barrier properties. The EGCG/HPMC complex film was able to control EGCG release by tuning pH or temperature of the release medium. Furthermore, incorporation of CuS nanoparticles into the film allowed it to triggers EGCG release in an on-demand fashion under near-infrared (NIR) exposure. Bacterial growth in glucose-free nutrient broth medium caused pH to rise (near pH 8.0), leading to transformation of EGCG from phenol type to phenolate ion and then quinone, allowing for spontaneous generation of H2O2 to kill bacteria. The complex films changed their color in response to bacterial growth because EGCG transformed from phenol type to quinone type under alkaline condition. The green synthesized EGCG/HPMC complex films can be used as a colorimetric pH indicator and an antibacterial material for wound dressing and food packaging applications.

Synthesis and characterization of Gd-DTPA/fucoidan/peptide complex nanoparticle and in vitro magnetic resonance imaging of inflamed endothelial cells.

P-selectin overexpressed on activated endothelial cells and platelets is a new target for treatment of cancers and cardiovascular diseases such as atherosclerosis and thrombosis. In this study, depolymerized low molecular weight fucoidan (LMWF8775) and a thermolysin-hydrolyzed protamine peptide (TPP1880) were prepared. TPP1880 and LMWF8775 were able to form self-assembled complex nanoparticles (CNPs). The formation of TPP1880/LMWF8775 CNPs was characterized by Fourier-transform infrared spectra, circular dichroism spectra and isothermal titration calorimetry. The CNPs selectively targeted PMA-stimulated, inflamed endothelial cells (HUVECs) with high expression of P-selectin. Gd-DTPA MRI contrast agent was successfully loaded in the CNPs with better T1 relaxivity and selectively accumulated in the activated HUVECs with increased MRI intensity and reduced cytotoxicity as compared to free Gd-DTPA. Our results suggest that the TPP1880/LMWF8775 CNPs may have potential in future for early diagnosis of cardiovascular diseases and cancers in which the endothelium is inflamed or activated.

Fucoidan-based, tumor-activated nanoplatform for overcoming hypoxia and enhancing photodynamic therapy and antitumor immunity.

Multifunctional nanoplatforms combined with photodynamic therapy (PDT) and anticancer drugs have shown great promising in cancer therapy. However, their efficacy is limited by the low specificity, low oxygen levels, and a tolerant tumor immune microenvironment. Herein, we developed a biocompatible theranostic nanoplatform (FM@VP) based on co-assembly of a nanocomplex formed by a functional polysaccharide fucoidan and a bioreducible polyamidoamine (PAMAM) dendrimer, a photosensitizer verteporfin (VP), and MnO2 nanoparticles (a tumor microenvironment responsive oxygen evolving nanomaterial) into a multifunctional nanoparticle cluster. The dendrimer-fucoidan polyionic nanocomplex (DFPN) specifically targeted P-selectin-overexpressed triple-negative breast cancer (TNBC) and the tumor-associated vasculature, and was sensitive to glutathione (GSH) in tumor. More importantly, this FM@VP nanocomplex simultaneously overcame tumor hypoxia, suppressed oncogenic signaling, and attenuated tumor-mediated immunosuppression, resulting in improving therapeutic efficacy of PDT while enhancing antitumor immunity and anti-metastasis. This discovery provides a powerful strategy for synergetic cancer targeting/photodynamic/immunotherapy and could serve as a safe clinical translational approach.

Characterization and toxicology evaluation of low molecular weight chitosan on zebrafish.

Chitosan is suggested as no or low toxicity and biocompatible biomaterial. Digestion of chitosan to reduce molecular weight and formulate nanoparticle was generally used to improve efficiency for DNA or protein delivery. However, the toxicity of low-molecular-weight chitosan (LMWCS) towards freshwater fishes has not been well evaluated. Here, we reported the toxic mechanism of LMWCS using zebrafish (Danio rerio) liver (ZFL) cell line, zebrafish larvae, and adult fish. LMWCS rapidly induced cytotoxicity of ZFL cells and death of zebrafish. Cell membrane damaged by LMWCS reduced cell viability. Damaged membrane of epithelial cell in zebrafish larvae induced breakage of the yolk. Adult fish exhibited hypoxia before death due to multiple damages induced by LMWCS. Although the toxicity of LMWCS was revealed in zebrafish model, the toxicity was only present in pH < 7 and easy be neutralized by other negative ions. Collectively, these data improved a new understanding of LMWCS properties.

Development of bacterial cellulose/chitin multi-nanofibers based smart films containing natural active microspheres and nanoparticles formed in situ.

Nanofiber-based materials have recently gained increasing attention in food packaging, drug delivery, and biomedical applications. In this study, a multi-nanofibers composite film was developed based on bacterial cellulose nanofiber (BCNF)/chitin nanofiber (CNF) hybridization. The nanofibers were responsible for the formation of well-dispersed curcumin (Cur) micro/nanoparticles in the nanocomposite films. The release of Cur from the films were affected by CNF and the sizes of Cur particles formed in situ. The Cur particles reduced tensile strength and increased water vapor permeability of BCNF film. However, CNF improved the mechanical strength and barrier property of the Cur/BCNF/CNF composite film. Moreover, the multi-nanofibers composite film showed excellent dynamic antioxidant capacity and antibacterial activity, as well as was capable to monitor pH change and trace amount of boric acid. Results of this study suggested that the Cur/BCNF/CNF composite film can be used as a smart and active food packaging material.

A bioinspired hyperthermic macrophage-based polypyrrole-polyethylenimine (Ppy-PEI) nanocomplex carrier to prevent and disrupt thrombotic fibrin clots.

Fibrinolytic treatments for venous or arterial thrombotic syndromes using systemic administration of thrombolytics, such as streptokinase, can induce life-threatening bleeding complications. In this study, we offer the first proof of concept for a targeted photothermal fibrin clot prevention and reduction technology using macrophages loaded with polypyrrole-polyethylenimine nanocomplexes (Ppy-PEI NCs) and subjected to near-infrared radiation (NIR). We first show that the developed Ppy-PEI NCs could be taken up by defensive macrophages in vitro through endocytosis. The Ppy-PEI NCs generated local hyperthermia upon NIR treatment, which appeared to produce reactive oxygen species in Ppy-PEI NC-loaded macrophages. Preliminary evidence of efficacy as an antithrombotic tool is provided, in vitro, using fibrinogen-converted fibrin clots, and in vivo, in a rat femoral vascular thrombosis model generated by exposure to ferric chloride substance. The in vivo biocompatibility, photothermal behavior, biodistribution, and histological observation of cellular interactions with the Ppy-PEI NCs in the rat model provide rationale in support of further preclinical studies. This Ppy-PEI NC/NIR-based method, which uses a unique macrophage-guided targeting approach to prevent and lyse fibrin clots, may potentially overcome some of the disadvantages of current thrombolytic treatments. STATEMENT OF SIGNIFICANCE: Fibrinolytic treatments for venous or arterial thrombotic syndromes using systemic administration of thrombolytics, such as streptokinase, can induce life-threatening bleeding complications. In this study, we offer the first proof of concept for a targeted photothermal fibrin clot reduction technology using macrophages loaded with polypyrrole-polyethylenimine nanocomplexes (Ppy-PEI NCs) and subjected to near-infrared radiation (NIR). We first show that the developed Ppy-PEI NCs can be taken up by defensive macrophages in vitro through endocytosis. The Ppy-PEI NCs generated local hyperthermia upon NIR treatment, which appeared to produce reactive oxygen species in Ppy-PEI NC-loaded macrophages. Preliminary evidence of efficacy as an antithrombotic tool is provided, in vitro, using fibrinogen-converted fibrin clots, and in vivo, in a rat femoral vascular thrombosis model generated by exposure to ferric chloride substance. The in vivo biocompatibility, photothermal behavior, biodistribution, and histological observation of cellular interactions with the Ppy-PEI NCs in the rat model provide rationale in support of further preclinical studies. This Ppy-PEI NC/NIR-based method, which uses a unique macrophage-guided targeting approach to disintegrate fibrin clots, may potentially overcome some of the disadvantages of current thrombolytic treatments.

A novel injectable in situ forming gel based on carboxymethyl hexanoyl chitosan/hyaluronic acid polymer blending for sustained release of berberine.

An in situ forming gel based on simply blending carboxymethyl hexanoyl chitosan (CHC) with low molecular weight hyaluronic acid (LMW HA) was developed, without needing cross-linking, photopolymerization or thermal treatments. The CHC/LMW HA blends formed nanoparticles and then rapidly transformed into supermolecular hydrogels under stirring. The gel formation mechanism was examined by Förster resonance energy transfer (FRET). The gels were injectable, cytocompatible and biodegradable, and showed shape-persistent behavior and adhesive property. Berberine, an anti-apoptotic and anti-arthritis naturally occurring compound, was encapsulated within the CHC/LMW HA gels. The gels demonstrated a pH-responsive characteristic which were able to release berberine in a sustained manner at pH 6.0 (simulating inflamed arthritic articular cartilage) and the degradation rates were accelerated at pH 7.4 (simulating healed normal tissue). The berberine-loaded gels effectively protected chondrocytes against sodium nitroprusside-induced apoptosis. The gels may be potentially useful as an injectable system for intra-articular drug delivery and cartilage tissue engineering.

Development of nanocomposite scaffolds based on biomineralization of N,O-carboxymethyl chitosan/fucoidan conjugates for bone tissue engineering.

Bone tissue engineering holds great promise and clinical efficacy for the regeneration of bone defects. In this study, an amphoteric N,O-carboxymethyl chitosan (NOCC) and fucoidan (FD) were covalently cross-linked via an amidation reaction to synthesize NOCC/FD composite hydrogels. The hydrogels were lyophilized and then three-dimensional scaffolds with interconnected macropores were obtained. To enhance the mechanical properties and osteogenic activity, the NOCC/FD scaffolds were biomineralized for the growth of hydroxyapatite crystals. A comparative assessment of the structures, morphologies, and physical properties of the original and mineralized scaffolds were performed by SEM, EDS, X-ray diffraction and FT-IR analysis. FD regulated the growth of hydroxyapatite nanocrystallites (n-HAp) and thus the NOCC/FD scaffolds showed better mineralization efficiency than NOCC scaffolds. The compressive strength of the scaffolds was greatly enhanced after mineralization with n-HAp. The n-HAp/NOCC/FD scaffolds enhanced the proliferation, ALP activity, and mineralization of osteoblast cells more strongly than the original and mineralized NOCC scaffolds. Hence, the n-HAp-mineralized NOCC/FD scaffolds may prove to be an excellent and versatile scaffold for bone tissue engineering.

Temperature/pH/Enzyme Triple-Responsive Cationic Protein/PAA-b-PNIPAAm Nanogels for Controlled Anticancer Drug and Photosensitizer Delivery against Multidrug Resistant Breast Cancer Cells.

The tumor microenvironments are often acidic and overexpress specific enzymes. In this work, we synthesized a poly(AA-b-NIPAAm) copolymer (PAA-b-PNIPAAm) using a reversible addition-fragmentation chain transfer (RAFT) polymerization method. PAA-b-PNIPAAm and a cationic protein (protamine) were self-assembled into nanogels, which effectively reduced the cytotoxicity of protamine. The protamine/PAA-b-PNIPAAm nanogels were responsive to the stimuli including temperature, pH, and enzyme due to disaggregation of PAA-b-PNIPAAm, change in random coil/α-helix conformation of protamine, and enzymatic hydrolysis of the protein. Changing the pH from 7.4 to a lowered pHe (6.5-5.0) resulted in an increase in mean particle size and smartly converted surface charge from negative to positive. The cationic nanogels easily passed through the cell membrane and enhanced intracellular localization and accumulation of doxorubicin-loaded nanogels in multidrug resistant MCF-7/ADR breast cancer cells. Cold shock treatment triggered rapid intracellular release of doxorubicin against P-glycoprotein (Pgp)-mediated drug efflux, showing significantly improved anticancer efficacy as compared with free DOX. Furthermore, the nanogels were able to carry a rose bengal photosensitizer and caused significant damage to the multidrug resistant cancer cells under irradiation. The cationic nanogels with stimuli-responsive properties show promise as drug carrier for chemotherapy and photodynamic therapy against cancers.