Tumor Microenvironmental pH and Enzyme Dual Responsive Polymer-Liposomes for Synergistic Treatment of Cancer Immuno-Chemotherapy.

Despite recent advances in tumor treatment through cancer immunotherapy, the efficacy of this approach remains to be improved. Looking forward to high rates of objective clinical response, cancer immunotherapy combined with chemotherapy has gained increasing attention recently. Here, we constructed liposomes with matrix metalloproteinases (MMPs) responsive moiety and PD-L1 inhibitor conjugate combine with low dose chemotherapy to achieve enhanced antitumor efficacy. Upon introduction of the pH-responsive polymer to LPDp, the coassembly could be almost stable in physiological conditions and tumor microenvironments and release the loaded cargos at the lysosome. MMP-2 enzyme extracellularly secreted by the B16F10 cells could cleave the cross-linker and liberate the PD-L1 inhibitor effectively disrupting the PD-1/PD-L1 interaction in vitro. Low dose DOX encapsulated in the LPDp was capable of sensitizing B16F10 cells to CTLs by inducing overexpression of M6PR on tumor cell membranes. In comparison with free PD-L1 inhibitor, LPDp improved the biodistribution and on-demand release of the peptide inhibitor in tumor regions following administration. LPDp achieved the optimal tumor suppression efficiency (∼78.7%), which demonstrated the significantly enhanced antitumor effect ( P < 0.01) than that of LPp (∼57.5%) as well as that of LD (<40%), attributing to synergistic contribution from the substantial increase in M6PR expression on tumor cells and the blockade of immune checkpoints. This strategy provides a strong rationale for combining standard-of-care chemotherapy with relative nontoxic and high specific immunotherapy.

Long-term combined blockade of CXCR4 and PD-L1 with in vivo reassembly for intensive tumor interference.

Negative immunoregulatory signal (PD-L1, CXCR4, et al.) and weak immunogenicity elicited immune system failing to detect and destroy cancerous cells. CXCR4 blockade promoted T cell tumor infiltration and increased tumor sensitivity to anti-PD-L1 therapy. Here, pH-responsive reassembled nanomaterials were constructed with anti-PD-L1 peptide and CXCR4 antagonists grafting (APAB), synergized with photothermal therapy for melanoma and breast tumor interference. The self-assembled APAB nanoparticles accumulated in the tumor and rapidly transformed into nanofibers in response to the acidic tumor microenvironment, leading to the exposure of grafted therapeutic agents. APAB enabling to reassemble around tumor cells and remained stable for over 96 h due to the aggregation induced retention (AIR) effect, led to long-term efficiently combined PD-L1 and CXCR4 blockade. Photothermal efficiency (ICG) induced immunogenic cell death (ICD) of tumor cells so as to effectively improve the immunogenicity. The combined therapy (ICG@APAB) could effectively inhibit the growth of primary tumor (∼83.52%) and distant tumor (∼76.24%) in melanoma-bearing mice, and significantly (p < 0.05) prolong the survival time over 42 days. The inhibition assay on tumor metastasis in 4 T1 model mice exhibited ICG@APAB almostly suppressed the occurrence of lung metastases and the expression levels of CD31, MMP-9 and VEGF in tumor decreased by 82.26%, 90.45% and 41.54%, respectively. The in vivo reassembly strategy will offer novel perspectives benefical future immunotherapies and push development of combined therapeutics into clinical settings.

3-D culture of human umbilical vein endothelial cells with reversible thermosensitive hydroxybutyl chitosan hydrogel.

The aim of this study was to present a non-trypsin 3D cell culture method with a reversible thermosensitive HBCS hydrogel. In this study, hydroxybutyl chitosan (HBCS) was synthesized by grafting hydroxybutyl groups on chitosan molecule chains. The prepared HBCS was water-soluble, and the reversible phase transformation temperature was 26 °C. Scanning electron microscope images illuminated the 3-D network of hydrogel formed irregular porous structure which ranged from 50-250 µm. Cell viability assay indicated that HBCS solution could promote the proliferation of human umbilical vein endothelial cells (HUVECs), and the boost of proliferation was enhanced with the increase of HBCS concentration. HBCS had no harm to the nitric oxide (NO) synthesis functionality of HUVECs. HUVECs could grow and reproduce inside the hydrogel, and showed good vitality after 14-days culture. Meanwhile, cells cultured inside the hydrogel could be passaged successively through the reversible phase transformation process of HBCS. The results revealed that HBCS have the potential to be used for 3-D cell culture without the use of trypsin.

Sequential treatment for diabetic foot ulcers in dialysis patients: A case report.

BACKGROUND: Diabetic foot ulcers (DFUs) are common in patients with diabetes, especially those undergoing hemodialysis. In severe cases, these ulcers can cause damage to the lower extremities and lead to amputation. Traditional treatments such as flap transposition and transfemoral amputation are not always applicable in all cases. Therefore, there is a need for alternative treatment methods. CASE SUMMARY: This report describes a 62-year-old female patient who was admitted to the hospital with plantar and heel ulcers on her left foot. The patient had a history of renal failure and was undergoing regular hemodialysis. Digital subtraction angiography showed extensive stenosis and occlusion in the left superficial femoral artery, left peroneal artery and left posterior tibial artery. Following evaluation by a multidisciplinary team, the patient was diagnosed with type 2 DFUs (TEXAS 4D). Traditional treatments were deemed unsuitable, and the patient was treated with endovascular surgery in the affected area, in addition to supportive medical treatment, local debridement, and sequential repair using split-thickness skin and tissue-engineered skin grafts combined with negative pressure treatment. After four months, the wound had completely healed, and the patient was able to walk with a walking aid. CONCLUSION: This study demonstrates a new treatment method for DFUs was successful, using angioplasty, skin grafts, and negative pressure.

Self-assembled polymeric nanoparticles based on oleic acid-grafted chitosan oligosaccharide: biocompatibility, protein adsorption and cellular uptake.

Oleic acid-grafted chitosan oligosaccharide (OA-g-CSO) was synthesized to prepare self-assembled nanoparticles by sonication at physiological pH value (7.4). The nanoparticles appeared to be spherical in shape with a diameter of 158.1 ± 64.3 nm. The biocompatibility of OA-g-CSO nanoparticles was evaluated in vitro via MTT assay and hemolysis test. The nanoparticles showed no cytotoxicity to mouse embryo fibroblasts and the hemolysis rates came well within permissible limits (<2 %) in the tested conditions. When incubated with bovine calf serum, the protein adsorption on the surface of OA-g-CSO nanoparticles was concentration-dependent, and the amount of bovine serum albumin was in the highest proportion of the total amount of adsorbed proteins. Cellular uptake rate was evaluated by incubating fluorescence labeled OA-g-CSO nanoparticles with human lung carcinoma cells (A549). OA-g-CSO nanoparticles could be taken up by A549 cells, and the uptake rates increased with incubation time and particle concentration.

Preparation and evaluation of oleoyl-carboxymethy-chitosan (OCMCS) nanoparticles as oral protein carriers.

Oleoyl-carboxymethy chitosan (OCMCS) nanoparticles based on chitosan with different molecular weights (50, 170 and 820 kDa) were prepared by self-assembled method. The nanoparticles had spherical shape, positive surface charges and the mean diameters were 157.4, 274.1 and 396.7 nm, respectively. FITC-labeled OCMCS nanoparticles were internalized via the intestinal mucosa and observed in liver, spleen, intestine and heart following oral deliverance to carps (Cyprinus carpio). Extracellular products (ECPs) of Aeromonas hydrophila as microbial antigen was efficiently loaded to form OCMCS-ECPs nanoparticles and shown to be sustained release in PBS. Significantly higher (P < 0.05) antigen-specific antibodies were detected in serum after orally immunized with OCMCS-ECPs nanoparticles than that immunized with ECPs alone and non-immunized in control group in carps. These results implied that amphiphilic modified chitosan nanoparticles had great potential to be applied as carriers for the oral administration of protein drugs.

Collagen-based biocomposites inspired by bone hierarchical structures for advanced bone regeneration: ongoing research and perspectives.

Bone is a hard-connective tissue composed of matrix, cells and bioactive factors with a hierarchical structure, where the matrix is mainly composed of type I collagen and hydroxyapatite. Collagen fibers assembled by collagen are the template for mineralization and make an important contribution to bone formation and the bone remodeling process. Therefore, collagen has been widely clinically used for bone/cartilage defect regeneration. However, pure collagen implants, such as collagen scaffolds or sponges, have limitations in the bone/cartilage regeneration process due to their poor mechanical properties and osteoinductivity. Different forms of collagen-based composites prepared by incorporating natural/artificial polymers or bioactive inorganic substances are characterized by their interconnected porous structure and promoting cell adhesion, while they improve the mechanical strength, structural stability and osteogenic activities of the collagen matrix. In this review, various forms of collagen-based biocomposites, such as scaffolds, sponges, microspheres/nanoparticles, films and microfibers/nanofibers prepared by natural/synthetic polymers, bioactive ceramics and carbon-based materials compounded with collagen are reviewed. In addition, the application of collagen-based biocomposites as cytokine, cell or drug (genes, proteins, peptides and chemosynthetic) delivery platforms for proangiogenesis and bone/cartilage tissue regeneration is also discussed. Finally, the potential application, research and development direction of collagen-based biocomposites in future bone/cartilage tissue regeneration are discussed.

Bridging micro/nano-platform and airway allergy intervention.

Allergic airway diseases, with incidence augmenting visibly as industrial development and environmental degradation, are characterized by sneezing, itching, wheezing, chest tightness, airway obstruction, and hyperresponsiveness. Current medical modalities attempt to combat these symptoms mostly by small molecule chemotherapeutants, such as corticosteroids, antihistamines, etc., via intranasal approach which is one of the most noninvasive, rapid-absorbed, and patient-friendly routes. Nevertheless, inherent defects for irritation to respiratory mucosa, drug inactivation and degradation, and rapid drug dispersal to off-target sites are inevitable. Lately, intratracheal micro/nano therapeutic systems are emerging as innovative alternatives for airway allergy interventions. This overview introduces several potential application directions of mic/nano-platform in the treatment of airway allergic diseases, including carriers, therapeutic agents, and immunomodulators. The improvement of the existing drug therapy of respiratory allergy management by micro/nano-platform is described in detail. The challenges of the micro/nano-platform nasal approach in the treatment of airway allergy are summarized and the development of micro/nano-platform is also prospected. Although still a burgeoning area, micro/nano therapeutic systems are gradually turning to be realistic orientations as crucial future alternative therapeutic options in allergic airway inflammation interventions.

Bridging nanoplatform and vaccine delivery, a landscape of strategy to enhance nasal immunity.

Vaccination is an urgently needed and effective option to address epidemic, cancers, allergies, and other diseases. Nasal administration of vaccines offers many benefits over needle-based injection including high compliance and less risk of infection. Inactivated or attenuated vaccines as convention vaccine present potential risks of pathogenic virulence reversal, the focus of nasal vaccine development has shifted to the use of next-generation (subunit and nucleic acid) vaccines. However, subunit and nucleic acid vaccine intranasally have numerous challenges in development and utilization due to mucociliary clearance, mucosal epithelial tight junction, and enzyme/pH degradation. Nanoplatforms as ideal delivery systems, with the ability to enhance the retention, penetration, and uptake of nasal mucosa, shows great potential in improving immunogenic efficacy of nasal vaccine. This review provides an overview of delivery strategies for overcoming nasal barrier, including mucosal adhesion, mucus penetration, targeting of antigen presenting cells (APCs), enhancement of paracellular transportation. We discuss methods of enhancing antigen immunogenicity by nanoplatforms as immune-modulators or multi-antigen co-delivery. Meanwhile, we describe the application status and development prospect of nanoplatforms for nasal vaccine administration. Development of nanoplatforms for vaccine delivery via nasal route will facilitate large-scale and faster global vaccination, helping to address the threat of epidemics.

Exploiting autophagy-regulative nanomaterials for activation of dendritic cells enables reinforced cancer immunotherapy.

Dendritic cells (DCs), as the most powerful antigen presenting cells, play a critical role in regulating immune response and anti-tumor process. However, the immunosuppressive cells and factors resided in the tumor microenvironment (TME) pose various challenges that can subvert competent DC function comprising antigen presentation and immune initiation. In this setting, developing potent strategies to improve the function of DCs is critically required for improving the efficacy of tumor immunotherapy. Autophagy is found to be closely associated to the various functions of DCs under physiological and pathological conditions. Especially, nanomaterials (NMs) can engage in the disorder and regularity of autophagy to modulate their metabolism and function of DCs. Reasonable design of nanomaterials with autophagy regulation is of great significance to activate DCs and enhance its immunological functions, provoking robust and durable antitumor immunity. In this review, we study the design and optimization of nanomaterials with the function of regulating DCs autophagy, discuss the main mechanism of DCs autophagy induced by nanomaterials and its application in tumor immunotherapy, promoting the progress and development of cancer immunotherapy strategies in the future.

Reshaping hypoxia and silencing CD73 via biomimetic gelatin nanotherapeutics to boost immunotherapy.

The ubiquitous hypoxic microenvironment at the tumor site helps to regulate hypoxic inducible factor (HIF-1α), up-regulate downstream CD73-adenosine (CD73-ADO) pathways, and further result in effector T cell function exhaustion, which is regarded as a crucial adverse factor in the poor clinical efficacy of immune checkpoint blockade therapy (ICB). How to reshape hypoxic microenvironment and silence CD73 remains a huge challenge to improve ICB therapeutic outcomes. In this study, cancer cell membrane-camouflaged gelatin nanoparticles (CSG@B16F10) were designed to co-deliver oxygen-generating agent catalase (CAT) and CD73siRNA, thus enhancing tumor oxygenation and alleviating CD73-ADO pathway-mediated T cell immunosuppression. The fabricated biomimetic nanoparticles could efficiently achieve immune evading and homologous targeting by virtue of the retention of cancer cell membrane protein. Matrix metalloproteinases (MMP)-responsive gelatin nanoparticles were gradually disintegrated to accelerate the release of payloads. Rapidly released CAT was found to relieve tumor hypoxia by generating endogenous oxygen, while CD73siRNA effectively silenced target gene, synergically inhibiting CD73 protein expression and facilitating T-cell-specific immunity. Upon introduction of CSG@B16F10 in melanoma-bearing mice, PD-L1 checkpoint blockade achieved optimal tumor suppression (∼83%). The enhanced immune efficacy was mainly manifested by enhanced cytotoxic T cell (CTL), reduced regulatory T cells (Tregs), and increased anti-tumor cytokine secretion. This work presents a new paradigm for the ideal design of biomimetic nanoplatforms and the synergistic treatment of hypoxia alleviation and CD73 silence, greatly promising for enhancing clinical immune potency of PD-1/PD-L1 immune checkpoint blockade.

MMP-responsive transformation nanomaterials with IAP antagonist to boost immune checkpoint therapy.

The clinical effect of immune checkpoint therapy is limited by the poor blocking efficiency of immune checkpoints and the insufficient infiltration of tumor-specific T cells. Here, we constructed enzyme-responsive PVA-peptide conjugates (PPCs) to achieve re-assembly with enhanced accumulation in the tumor region, enable enhanced PD-L1 occupancy and improve the blocking efficiency. The self-assembled PPC-1 nanoparticles can enter tumor environment, whereas the enzyme-cleavable peptide was digested under overgenerated matrix metalloproteinases (MMP). The accumulated PPC-1 simultaneously transformed into ß-sheet fibrous structures around the solid tumor and remained stable for over 96 h, which led to efficiently interrupting the PD-1/PD-L1 interaction. Upon introduction of the IAP antagonists, the non-classical NF-κB pathway of dendritic cells was activated and increased the infiltration of T cells in tumors. With the synergistic contribution of IAP antagonists from the substantial increase in expression of chemokines (CCL5 and CXCL9) and adequate T-cell infiltration in tumor sites, PPC-1 improved the biodistribution and accumulation of PD-L1 antagonists in tumor regions ultimately realizing higher-performance (P < 0.01) tumor growth inhibition efficiency (~80%) than PPC-2 group (~58%) in B16F10 tumor-bearing mice. The growth of the second tumor at the distal end was obviously inhibited (P < 0.01) after the resection of the primary tumor. The combined efficacy was similar to that observed in a Pan02 pancreatic cancer tumor model. This strategy aims to offer novel perspective for the development of locational assembly platforms in vivo and the optimal design of immune checkpoint combination therapy.

Mussel-inspired adhesive and polypeptide-based antibacterial thermo-sensitive hydroxybutyl chitosan hydrogel as BMSCs 3D culture matrix for wound healing.

Hydrogels have gained great attentions as wound dressing. Binding to the tissue and preventing wound infection were the basic requirements for an "ideal dressing". We employed l-DOPA and ε-Poly-l-lysine to modify thermo-sensitive hydroxybutyl chitosan (HBC) to obtain (l-DOPA) - (ε-Poly-l-lysine)-HBC hydrogels (eLHBC). The eLHBC exhibited an almost 1.5 fold (P < 0.01) increase in wet adhesion strength compared to HBC. Upon the introduction of ε-Poly-l-lysine, eLHBC presented inherent antimicrobial property and prevented wound infection and inflammation response. Bone marrow mesenchymal stem cells (BMSCs) encapsulated in the eLHBC (BMSCs ⊂ eLHBC) could secret cytokins and growth factors via paracrine and promote the migration of fibroblast cells. BMSCs ⊂ eLHBC enhanced the complete skin-thickness wound healing via promoting collagen deposition and inhibiting infection and inflammation in vivo with wound closure rate being above 99 % after 15 days. The bioinspired, tissue-adhesive eLHBC could serve as advanced wound dressings for facilitating tissue repair and regeneration.

Hypoxia-modulatory nanomaterials to relieve tumor hypoxic microenvironment and enhance immunotherapy: Where do we stand?

The past several years have witnessed the blooming of emerging immunotherapy, as well as their therapeutic potential in remodeling the immune system. Nevertheless, with the development of biological mechanisms in oncology, it has been demonstrated that hypoxic tumor microenvironment (TME) seriously impairs the therapeutic outcomes of immunotherapy. Hypoxia, caused by Warburg effect and insufficient oxygen delivery, has been considered as a primary construction element of TME and drawn tremendous attention in cancer therapy. Multiple hypoxia-modulatory theranostic agents have been facing many obstacles and challenges while offering initial therapeutic effect. Inspired by versatile nanomaterials, great efforts have been devoted to design hypoxia-based nanoplatforms to preserve drug activity, reduce systemic toxicity, provide adequate oxygenation, and eventually ameliorate hypoxic-tumor management. Besides these, recently, some curative and innovative hypoxia-related nanoplatforms have been applied in synergistic immunotherapy, especially in combination with immune checkpoint blockade (ICB), immunomodulatory therapeutics, cancer vaccine therapy and immunogenic cell death (ICD) effect. Herein, the paramount impact of hypoxia on tumor immune escape was initially described and discussed, followed by a comprehensive overview on the design tactics of multimodal nanoplatforms based on hypoxia-enabled theranostic agents. A variety of nanocarriers for relieving tumor hypoxic microenvironment were also summarized. On this basis, we presented the latest progress in the use of hypoxia-modulatory nanomaterials for synergistic immunotherapy and highlighted current challenges and plausible promises in this area in the near future. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy, emerging as a novel treatment to eradicate malignant tumors, has achieved a measure of success in clinical popularity and transition. However, over the last decades, hypoxia-induced tumor immune escape has attracted enormous attention in cancer treatment. Limitations of free targeting agents have paved the path for the development of multiple nanomaterials with the hope of boosting immunotherapy. In this review, the innovative design tactics and multifunctional nanocarriers for hypoxia alleviation are summarized, and the smart nanomaterial-assisted hypoxia-modulatory therapeutics for synergistic immunotherapy and versatile biomedical applications are especially highlighted. In addition, the challenges and prospects of clinical transformation are further discussed.

Nanosystems as curative platforms for allergic disorder management.

Allergy, IgE-mediated inflammatory disorders including allergic rhinitis, asthma, and conjunctivitis, affects billions of people worldwide. Conventional means of allergy management include allergen avoidance, pharmacotherapy, and emerging therapies. Among them, chemotherapeutant intake via oral, intravenous, and intranasal routes is always the most common mean. Although current pharmacotherapy exhibit splendid anti-allergic effects, short in situ retention, low bioavailability, and systemic side effects are inevitable. Nowadays, nanoplatforms have provided alternative therapeutic options to obviate the existing weakness via enhancing the solubility of hydrophobic therapeutic agents, achieving in situ drug accumulation, exhibiting controlled and long-time drug release at lesion areas, and providing multi-functional therapeutic strategies. Herein, we highlight the clinical therapeutic strategies and deal with characteristics of the nanoplatform design in allergy interventions via intratracheal, gastrointestinal, intravenous, and ocular paths. The promising therapeutic utilization in a variety of allergic disorders is discussed, and recent perspectives on the feasible advances of nanoplatforms in allergy management are also exploited.

Adsorption characteristics of residual oil on amphiphilic chitosan derivative.

In this study, a novel chitosan-based polymeric surfactant, H-Oleoyl-Carboxymethyl chitosan was used as a coagulation agent for cleaning residual oil. The characteristics of H-Oleoyl-Carboxymethyl chitosan were investigated by FTIR and XRD. And the adsorption capacities of chitosan and H-O-CMCS for removing the residue oil from the wastewater of oil extraction have been investigated. H-O-CMCS exhibited a greater rate than chitosan in cleaning the residual oil from the wastewater of oil extraction at the optimum conditions. Equilibrium study, Langmuir/Freundlich adsorption models and the pseudo first- and second-order kinetic models were applied to describe the mechanism of adsorption experiments. The experimental data fitted well with the Langmuir model and the second-order kinetic model. Regeneration studies, using by the roasting and rinsing method, were undergone for three successive adsorption/desorption processes. H-O-CMCS still retained the residual oil removal capacity after regeneration.

Effect of cornuside on experimental sepsis.

This study was conducted to investigate the efficacy of cornuside, a secoiridoid glucoside compound, in cultured macrophages as well as in an experimental model of sepsis induced by cecal ligation and puncture (CLP) in rats. Cornuside was added to cultured macrophages at different concentrations, and all CLP rats were randomized to receive an intravenous injection of the corresponding drug followed by observation of its antisepsis effect. Our results showed that cornuside downregulated the levels of TNF- alpha, IL-6, and NO production in a dose-dependent manner in activated macrophages, while it upregulated the level of IL-10. Intravenous injection of cornuside or imipenem alone or in combination reduced CLP-induced lethality in rats after CLP. In addition, serum levels of TNF- alpha, IL-6, triggering receptor expressed on myeloid cells, and endotoxin were downregulated. On the other hand, the serum levels of IL-10 were upregulated. Decreased bacterial counts in blood, peritoneum, spleen, liver, and mesenteric lymph nodes and decreased myeloperoxidase in lung, liver, and small intestine also were found after cornuside injection. These data indicate that the antisepsis therapeutic effect of cornuside is mediated by decreased local and systemic levels of a wide spectrum of inflammatory mediators. This work provides first evidence for the clinic use of cornuside as a new immunomodulatory drug that has the capacity to inhibit the inflammatory response in sepsis.

Cornuside attenuates apoptosis and ameliorates mitochondrial energy metabolism in rat cortical neurons.

Cornuside, a secoiridoid glucoside compound, was isolated from the fruit of Cornus officinalis Sieb. et Zucc. The present study elucidates the effects of cornuside on cultured rat cortical neuron damage induced by oxygen-glucose deprivation. The results show that cornuside treatment obviously attenuates apoptosis and ameliorates mitochondrial energy metabolism in rat cortical neurons by increasing the cell survival rate, mitochondrial antioxidant enzyme activities, mitochondrial respiratory enzyme activity, mitochondrial respiratory control ratio and the ATP content, and by decreasing the mitochondrial malondialdehyde content, lactate dehydrogenase leakage rate, intracellular Ca(2+) level and caspase-3 activity in a concentration-dependent manner. These findings indicate that cornuside has protective potential against cerebral ischemic injury, and its protective effects may be due to the suppression of intracellular Ca(2+) elevation and caspase-3 activity, and improvements in mitochondrial energy metabolism and antioxidant properties.

Investigation of polymeric amphiphilic nanoparticles as antitumor drug carriers.

In this paper, polymeric amphiphilic nanoparticles based on oleoyl-chitosan (OCH) with different degrees of substitution (DS, 5%, 11% and 27%) were prepared by Oil/Water emulsification method. Mean diameters of the nanoparticles were 327.4 nm, 255.3 nm and 192.6 nm, respectively. Doxorubicin (DOX) was efficiently loaded into OCH nanoparticles and provided a sustained released after a burst release in PBS. These nanoparticles showed no cytotoxicity to mouse embryo fibroblasts (MEF) and low hemolysis rates (<5%). The results of SDS-PAGE indicated that bovine calf serum (BCS) adsorption on OCH nanoparticles was inhibited by smaller particle size. Cellular uptake was evaluated by incubating fluorescence labeled OCH nanoparticles with human lung carcinoma cells (A549) and mouse macrophages (RAW264.7). Cellular uptake of OCH nanoparticles was time--and concentration--dependent. Finding the appropriate incubation time and concentration of OCH nanoparticles used as drug carriers might decrease phagocytic uptake, increase cancer cell uptake and ultimately improve therapeutic efficiency of antitumor therapeutic agents.

Injectable thermosensitive hydrogel based on chitosan and quaternized chitosan and the biomedical properties.

A novel injectable thermosensitive hydrogel (CS-HTCC/alpha beta-GP) was successfully designed and prepared using chitosan (CS), quaternized chitosan (HTCC) and alpha,beta-glycerophosphate (alpha,beta-GP) without any additional chemical stimulus. The gelation point of CS-HTCC/alpha beta-GP can be set at a temperature close to normal body temperature or other temperature above 25 degrees C. The transition process can be controlled by adjusting the weight ratio of CS to HTCC, or different final concentration of alpha,beta-GP. The optimum formulation is (CS + HTCC) (2% w/v), CS/HTCC (5/1 w/w) and alpha,beta-GP 8.33% or 9.09% (w/v), where the sol-gel transition time was 3 min at 37 degrees C. The drug released over 3 h from the CS-HTCC/alpha,beta-GP thermosensitive hydrogel in artificial saliva pH 6.8. In addition, CS-HTCC/alpha,beta-GP thermosensitive hydrogel exhibited stronger antibacterial activity towards two periodontal pathogens (Porphyromonas gingivalis, P.g and Prevotella intermedia, P.i). CS-HTCC/alpha, beta-GP thermosensitive hydrogel was a considerable candidate as a local drug delivery system for periodontal treatment.