Inpatient Outcomes of Patients Undergoing Robot-Assisted versus Laparoscopic Radical Cystectomy for Bladder Cancer: A National Inpatient Sample Database Study.

Background: Bladder cancer is a common urinary tract malignancy. Minimally invasive radical cystectomy has shown oncological outcomes comparable to the conventional open surgery and with advantages over the open procedure. However, outcomes of the two main minimally invasive procedures, robot-assisted and pure laparoscopic, have yet to be compared. This study aimed to compare in-hospital outcomes between these two techniques performed for patients with bladder cancer. Methods: This population-based, retrospective study included hospitalized patients aged ≥ 50 years with a primary diagnosis of bladder cancer who underwent robot-assisted or pure laparoscopic radical cystectomy. All patient data were extracted from the US National Inpatient Sample (NIS) database 2008-2018 and were analyzed retrospectively. Primary outcomes were in-hospital mortality, prolonged length of stay (LOS), and postoperative complications. Results: The data of 3284 inpatients (representing 16,288 US inpatients) were analyzed. After adjusting for confounders, multivariable analysis revealed that patients who underwent robot-assisted radical cystectomy had a significantly lower risk of in-hospital mortality (adjusted OR [aOR], 0.50, 95% CI: 0.28-0.90) and prolonged LOS (aOR, 0.63, 95% CI: 0.49-0.80) than those undergoing pure laparoscopic cystectomy. Patients who underwent robot-assisted radical cystectomy had a lower risk of postoperative complications (aOR, 0.69, 95% CI: 0.54-0.88), including bleeding (aOR, 0.73, 95% CI: 0.54-0.99), pneumonia (aOR, 0.49, 95% CI: 0.28-0.86), infection (aOR, 0.55, 95% CI: 0.36-0.85), wound complications (aOR, 0.33, 95% CI: 0.20-0.54), and sepsis (aOR, 0.49, 95% CI: 0.34-0.69) compared to those receiving pure laparoscopic radical cystectomy. Conclusions: Patients with bladder cancer, robot-assisted radical cystectomy is associated with a reduced risk of unfavorable short-term outcomes, including in-hospital mortality, prolonged LOS, and postoperative complications compared to pure laparoscopic radical cystectomy.

Biomineralization-Inspired Anti-Caries Strategy Based on Multifunctional Nanogels as Mineral Feedstock Carriers.

Background: Dentin caries remains a significant public concern, with no clinically viable material that effectively combines remineralization and antimicrobial properties. To address this issue, this study focused on the development of a bio-inspired multifunctional nanogel with both antibacterial and biomineralization properties. Methods: First, p(NIPAm-co-DMC) (PNPDC) copolymers were synthesized from N-isopropylacrylamide (NIPAm) and 2-methacryloyloxyethyl-trimethyl ammonium chloride (DMC). Subsequently, PNPDC was combined with γ-polyglutamic acid (γ-PGA) through physical cross-linking to form nanogels. These nanogels served as templates for the mineralization of calcium phosphate (Cap), resulting in Cap-loaded PNPDC/PGA nanogels. The nanogels were characterized using various techniques, including TEM, particle tracking analysis, XRD, and FTIR. The release properties of ions were also assessed. In addition, the antibacterial properties of the Cap-loaded PNPDC/PGA nanogels were evaluated using the broth microdilution method and a biofilm formation assay. The remineralization effects were examined on both demineralized dentin and type I collagen in vitro. Results: PNPDC/PGA nanogels were successfully synthesized and loaded with Cap. The diameter of the Cap-loaded PNPDC/PGA nanogels was measured as 196.5 nm at 25°C and 162.3 nm at 37°C. These Cap-loaded nanogels released Ca2+ and PO43- ions quickly, effectively blocking dental tubules with a depth of 10 µm and promoting the remineralization of demineralized dentin within 7 days. Additionally, they facilitated the heavy intrafibrillar mineralization of type I collagen within 3 days. Moreover, the Cap-loaded nanogels exhibited MIC50 and MIC90 values of 12.5 and 50 mg/mL against Streptococcus mutans, respectively, with an MBC value of 100 mg/mL. At a concentration of 50 mg/mL, the Cap-loaded nanogels also demonstrated potent inhibitory effects on biofilm formation by Streptococcus mutans while maintaining good biocompatibility. Conclusion: Cap-loaded PNPDC/PGA nanogels are a multifunctional biomimetic system with antibacterial and dentin remineralization effects. This strategy of using antibacterial nanogels as mineral feedstock carriers offered fresh insight into the clinical management of caries.

Accelerated Bone Reconstruction by the Yoda1 Bilayer Membrane via Promotion of Osteointegration and Angiogenesis.

Guided bone regeneration membranes are widely used to prevent fibroblast penetration and facilitate bone defect repair by osteoblasts. However, the current clinically available collagen membranes lack bone induction and angiogenic capacities, exhibiting limited bone regeneration. The mechanically sensitive channel, Piezo1, which is activated by Yoda1, has been reported to play crucial roles in osteogenesis and angiogenesis. Nevertheless, the application of Yoda1 alone is unsustainable to maintain this activity. Therefore, this study fabricates a Yoda1-loading bilayer membrane using electrospinning technology. Its inner layer in contact with the bone defect is composed of vertically aligned fibers, which regulate the proliferation and differentiation of cells, release Yoda1, and promote bone regeneration. Its outer layer in contact with the soft tissue is dense with oriented fibers by UV cross-linking, mainly preventing fibroblast infiltration and inhibiting the immune response. Furthermore, the loaded Yoda1 affects osteogenesis and angiogenesis via the Piezo1/RhoA/Rho-associated coiled-coil-containing protein kinase 1/Yes1-associated transcriptional regulator signaling pathway. The results reveal that the Yoda1 bilayer membrane is efficient and versatile in accelerating bone regeneration, suggesting its potential as a novel therapeutic agent for various clinical issues.

Near-infrared light-responsive multifunctional hydrogel releasing peptide-functionalized gold nanorods sequentially for diabetic wound healing.

Treatment for chronic diabetic wounds remains a clinical challenge. Wound healing process occurs in three phases: inflammation, proliferation and remodeling. Several factors including bacterial infection, decreased local angiogenesis and diminished blood supply delay wound healing. There is an urgent need to develop wound dressings with multiple biological effects for different stages of diabetic wound healing. Here, we develop a multifunctional hydrogel with two-stage sequential release upon near-infrared (NIR) stimulation, antibacterial activity and pro-angiogenic efficacy. This hydrogel consists of covalently crosslinked bilayer structure, with the lower thermoresponsive poly(N-isopropylacrylamide)/gelatin methacrylate (NG) layer and the upper highly stretchable alginate/polyacrylamide (AP) layer embedding different peptide-functionalized gold nanorods (AuNRs) in each layer. Antimicrobial peptide-functionalized AuNRs released from NG layer exert antibacterial effects. After NIR irradiation, the photothermal transition efficacy of AuNRs synergistically enhances bactericidal efficacy. The contraction of thermoresponsive layer also promotes the release of embedded cargos during early stage. The pro-angiogenic peptide-functionalized AuNRs released from AP layer promote angiogenesis and collagen deposition by accelerating fibroblast and endothelial cell proliferation, migration and tube formation during the subsequent healing phases. Therefore, the multifunctional hydrogel with effective antibacterial activity, pro-angiogenic efficacy and sequential release behaviors is a potential biomaterial for diabetic chronic wound healing.

A multifunctional nanocatalytic system based on Chemodynamic-Starvation therapies with enhanced efficacy of cancer treatment.

A multi-functional nanocatalytic system based on combined therapies has attracted considerable research attention in recent years due to its potential in the treatment of cancer. Herein, ZnO2@Au@ZIF-67 nanoparticles (NPs) based on hydroxyl radical (•OH) mediated chemodynamic therapy (CDT) and glucose-exhausting starvation therapy (ST) were constructed. Specifically, in the acidic tumor microenvironment (TME), the pH responsive decomposition of the shell ZIF-67 triggered the release of the Fenton-like catalyst Co2+, after which the exposed zinc peroxide (ZnO2) reacted with H2O (H+) to generate O2 and hydrogen peroxide (H2O2). The generated O2 could alleviate hypoxia in the TEM and interact with ultra-small Au NPs originally coated on ZnO2 to catalyze intracellular glucose and to produce another source of H2O2. While the glucose consumption caused the starvation of tumor cells, the generated H2O2 from dual sources reacted with the catalyst Co2+ to generate highly toxic •OH for CDT. Systematic in vitro and in vivo experiments were carried out to evaluate this nanocatalytic system, and the results showed an enhanced efficacy of this cancer therapy.

pH-responsive cinnamaldehyde-TiO2 nanotube coating: fabrication and functions in a simulated diabetes condition.

Current evidence has suggested that diabetes increases the risk of implanting failure, and therefore, appropriate surface modification of dental implants in patients with diabetes is crucial. TiO2 nanotube (TNT) has an osteogenic nanotopography, and its osteogenic properties can be further improved by loading appropriate drugs. Cinnamaldehyde (CIN) has been proven to have osteogenic, anti-inflammatory, and anti-bacterial effects. We fabricated a pH-responsive cinnamaldehyde-TiO2 nanotube coating (TNT-CIN) and hypothesized that this coating will exert osteogenic, anti-inflammatory, and anti-bacterial functions in a simulated diabetes condition. TNT-CIN was constructed by anodic oxidation, hydroxylation, silylation, and Schiff base reaction to bind CIN, and its surface characteristics were determined. Conditions of diabetes and diabetes with a concurrent infection were simulated using 22-mM glucose without and with 1-µg/mL lipopolysaccharide, respectively. The viability and osteogenic differentiation of bone marrow mesenchymal stem cells, polarization and secretion of macrophages, and resistance to Porphyromonas gingivalis and Streptococcus mutans were evaluated. CIN was bound to the TNT surface successfully and released better in low pH condition. TNT-CIN showed better osteogenic and anti-inflammatory effects and superior bacterial resistance than TNT in a simulated diabetes condition. These findings indicated that TNT-CIN is a promising, multifunctional surface coating for patients with diabetes needing dental implants. Graphical abstract.

Combining eDNA and morphological approaches to reveal the impacts of long-term discharges of shale gas wastewaters on receiving waters.

The potential threats of shale gas wastewater discharges to receiving waters is of great concern. In this study, chemical analyses and biomonitoring were performed three times in a small river that received treated wastewater over a two-year period. The results of chemical analyses showed that the concentrations of chloride, conductivity, barium, and strontium increased at the discharge site, but their concentrations decreased considerably farther downstream (≥500 m). The concentrations of toxic organic compounds (16 US EPA priority polycyclic aromatic hydrocarbons and 6 priority phthalates), trace metals (strontium, arsenic, zinc, copper, chromium, lead, cadmium, nickel, and neodymium), and natural radionuclides (40K, 238U, 226Ra, and 232Th) were comparable to the corresponding background values or did not exhibit obvious accumulation in sediments with continued discharge. Morphological and environmental DNA approaches were used to reveal the potential effects of wastewater discharges on aquatic ecosystems. The results showed that the community structure of benthic invertebrates was not altered by the long-term discharges of shale gas wastewaters. However, the biodiversity indices (richness and Shannon) from the two approaches showed inconsistencies, which were caused by multiple reasons, and that substrates had a strong influence on the morphological biodiversity indices. A multimetric index was proposed to further analyze morphological and environmental DNA data, and the results showed no significant difference between the upstream and downstream sites. Generally, the chemical and biological results both demonstrated that the discharges of shale gas wastewaters had limited impacts on river ecosystems within two years.

Characterization of microbial communities and functions in shale gas wastewaters and sludge: Implications for pretreatment.

As hydraulic fracturing (HF) practices keep expanding in China, a comparative understanding of biological characteristics of flowback and produced waters (FPW) and sludge in impoundments for FPW reserve will help propose appropriate treatment strategies. Therefore, in this study, the microbial communities and functions in impoundments that collected wastewaters from dozens of wells were characterized. The results showed that microbial richness and diversity were significantly increased in sludge compared with those in FPW. The vast majority of microorganisms found in FPW and sludge are organic degraders, providing the possibility of using these indigenous microorganisms to biodegrade organic compounds. Our laboratory findings first show that wastewater pretreatment using these microorganisms was effective, and organic compounds in FPW from different shale formations were removed by 35-68% within 72 h in a wide temperature range (8 - 30 â„ƒ). Meanwhile, highly toxic compounds such as phthalate esters (PAEs), polycyclic aromatic hydrocarbons (PAHs), and petroleum hydrocarbons were effectively eliminated in reactors. The main microorganisms, key functional genes, and putative pathways for alkanes, PAHs, and PAEs degradation were also identified.

A bi-layered membrane with micro-nano bioactive glass for guided bone regeneration.

Guided bone regeneration (GBR) is widely used to treat oral bone defects. However, the osteogenic effects are limited by the deficiency of the available barrier membranes. In this study, a novel bi-layer membrane was prepared by solvent casting and electrospinning. The barrier layer made of poly (lactic-co-glycolic acid) (PLGA) was smooth and compact, whereas the osteogenic layer consisting of micro-nano bioactive glass (MNBG) and PLGA was rough and porous. The mineralization evaluation confirmed that apatite formed on the membranes in simulated body fluid. Immersion in phosphate-buffered saline led to the degradation of the membranes with proper pH changes. Mechanical tests showed that the bi-layered membranes have stable mechanical properties under dry and wet conditions. The bi-layered membranes have good histocompatibility, and the MNBG/PLGA layer can enhance bone regeneration activity. This was confirmed by cell culture results, expression of osteogenic genes, and immunofluorescence staining of RUNX-related transcription factor 2 and osteopontin. Therefore, the bi-layered membranes could be a promising clinical strategy for GBR surgery.

Superhydrophobic hierarchical fiber/bead composite membranes for efficient treatment of burns.

One of the current challenges in burn wound care is the development of multifunctional dressings that can protect the wound from bacteria or organisms and promote skin regeneration and tissue reconstitution. To this end, we report the design and fabrication of a composite electrospun membrane, comprised of electrospun polylactide: poly(vinyl pyrrolidone)/polylactide: poly(ethylene glycol) (PLA:PVP/PLA:PEG) core/shell fibers loaded with bioactive agents, as a functionally integrated wound dressing for efficient burns treatment. Different mass ratios of PLA:PVP in the shell were screened to optimize mechanical, physicochemical, and biological properties, in addition to controlled release profiles of loaded antimicrobial peptides (AMPs) from the fibers for desirable antibacterial activity. Fibroblasts were shown to readily adhere and proliferate when cultured on the membrane, indicating good in vitro cytocompatibility. The introduction of PLA beads by electrospraying on one side of the membrane resulted in biomimetic micro-nanostructures similar to those of lotus leaves. This designer structure rendered the composite membranes with superhydrophobic property to inhibit the adhesion/spreading of exogenous bacteria and other microbes. The administration of the resulting composite fibrous membrane on burnt skin in an infected rat model led to faster healing than a conventional product (sterile silicone membrane) and control detailed herein. These composite fibrous membranes loaded with bioactive drugs provide an integrated strategy for promoting burn wound healing and skin regeneration. STATEMENT OF SIGNIFICANCE: To address an urgent need in complex clinical requirements on developing a new generation of wound dressings with integrated functionalities. This article reports research work on a hierarchical fiber/bead composite membranes design, which combines a lotus-leaf-like superhydrophobic surface with drugs preloaded in the core and shell of fibers for effective burn treatment. This demonstrates a balance between simplified preparation processes and increased multifunctionality of the wound dressings. The creation of hierarchically structured surfaces can be readily achieved by electrospinning, and the composite dressings possessed a considerable mechanical strength, effective wound exudate absorption and permeability, good biocompatibility, broad antibacterial ability and promoting wound healing etc. Thus, our work unveils a promising strategy for the development of functionally integrated wound dressings for burn wound care.

Novel ß-TCP/PVA bilayered hydrogels with considerable physical and bio-functional properties for osteochondral repair.

Cartilage repairing grafts have been widely studied, and osteochondral replacement hydrogels have proven to be an excellent method in research and clinical fields. However, it has been difficult to simultaneously solve three main issues in osteochondral replacement preparation: surface lubrication, overall mechanical support and good simulations of cell regeneration. A novel integrated bilayered hydrogel osteochondral replacement was constructed by blending polyvinyl alcohol (PVA) and ß-tricalcium phosphate (ß-TCP) in this study. Separated nano-ball milling with ultrasound dispersion prepared ß-TCP demonstrated suitable properties of tiny particle size, high purity and ideal distribution, improving the mechanical properties of the novel integrated hydrogel, and providing a cartilage-like lubrication effect and high biocompatibility, including cytocompatibility and osteogenesis. The reinforcement of ß-TCP and integrated molding technology enabled the hydrogel to demonstrate excellent component compatibility and good bonding between the two layers, which promoted the strengthening of the compression modulus and tensile modulus up to three times by mechanical testing. The surface lubrication properties of the novel osteochondral hydrogel were similar to the natural cartilage by friction coefficient characterization. The two layers of the novel integrated graft provided a considerable bio-function by co-culturing with chondrocytes and synovium mesenchymal stem cells: chondrocytes promoted adherence achieved by the upper density layer and better osteogenesis performance of the porous lower layer. The design of the bilayered ß-TCP/PVA osteochondral hydrogel is promising for use in articular cartilage repair.

Microparticle templating as a route to nanoscale polymer vesicles with controlled size distribution for anticancer drug delivery.

Polymer vesicles are self-assembled shells of amphiphilic block copolymers (BCPs) that have attracted tremendous interest due to their encapsulation ability and intracellular delivery of therapeutic agents. However, typical processes for the formation of polymer vesicles lead to ensembles of structures with a broad size distribution (from nanometer to micrometer scale) which result in a limitation for efficient cellular uptake. In this study, we present a simple and efficient approach for the fabrication of polymer vesicles with uniform nanoscale dimensions from template formation of electrosprayed particles in a high throughput manner. First, electrospraying was applied to produce micrometer-sized templates of a block copolymer before polymer vesicles were formed from the pre-prepared microparticles via rehydration. Four different biocompatible diblock and triblock copolymers were used to successfully fabricate polymer vesicles with uniform size around 150nm using this approach. Furthermore, we encapsulate anticancer drug doxorubicin (DOX) within the polymer vesicles via this method. The kinetics of cellular uptake (HeLa cell) and intracellular distribution of DOX-loaded polymer vesicles have been quntified and monitored by flow cytometry and confocal microscopy, respectively. The results show that our new method provides a promising way to fabricate drug-loaded polymer vesicles with controllable nanoscale size for intracellular anticancer drug delivery.

Glucosamine-modified polyethylene glycol hydrogel-mediated chondrogenic differentiation of human mesenchymal stem cells.

Glucosamine (GA) is an important cartilage matrix precursor for the glycosaminoglycan biochemical synthesis, and has positive effects on cartilage regeneration, particularly in osteoarthritis therapy. However, it has not been used as a bioactive group in scaffolds for cartilage repair widely. In this study, we synthesized modified polyethylene glycol (PEG) hydrogel with glucosamine and then encapsulated human bone mesenchymal stem cells (hBMSCs) in the hydrogel to induce the differentiation of hBMSCs into chondrocytes in three-dimensional culture. The GA-modified PEG hydrogels promoted the chondrogenesis of hBMSCs, particularly in the concentration of 5mM and 10mM. The subcutaneous transplantation of 10mM GA-modified hydrogels with hBMSCs formed cartilage-like blocks in vivo for 8weeks. Importantly, with glucosamine increase, the modified hydrogels down-regulated the fibrosis and hypertrophic cartilage markers in protein level. Therefore, glucosamine modified PEG hydrogels facilitated the chondrogenesis of hBMSCs, which might represent a new method for cartilage repair using a tissue-engineering approach.

Efficacy and prognosis of surgery combined with 125I seed implantation in treatment of recurrent glioma.

This study evaluated the efficacy of surgery combined with 125I seed implantation in the treatment of recurrent glioma, and analyzed prognosis-influencing factors. A total of 66 patients with recurrent gliomas in Yidu Central Hospital of Weifang were enrolled in the study from April, 2011 to March, 2014. Patients were randomly divided into a control and an observation group, with 33 patients in each group. Patients in the control group were treated with surgery alone, and those in the observation group received surgery combined with 125I seed implantation. Short-term curative effects in the two groups were compared using evaluation criteria for solid tumors. The comparison included the postoperative adverse reactions, the life quality (using the Karnofsky Performance Status or KPS), the survival time and prognostic factors (using the Kaplan-Meier survival, log-rank test and Cox regression analyses). Our results showed the objective response and disease control rates in the observation group were significantly higher than those in the control group (P<0.05). While no significant differences in postoperative adverse reactions were found between the two groups (P>0.05). The KPS score in the observation group was significantly higher than that in the control group at different time points after surgery (P<0.05). The survival rate and overall survival time of those in the observation group were significantly higher than those of the patients in the control group (P<0.05). The univariate analysis showed that preoperative KPS score, tumor pathological grade and degree of tumor resection were adverse factors influencing the prognosis of the patients (P<0.05). Also, multivariate Cox regression showed that preoperative KPS score, tumor pathological grade, and degree of tumor resection were independent risk factors of prognosis. Based on our findings, surgery combined with 125I seed implantation can improve the survival rate of patients with recurrent glioma and prolong their survival time. Tumor pathological grade, degree of tumor resection and KPS score are the most important factors influencing the prognosis.

Collagen based film with well epithelial and stromal regeneration as corneal repair materials: Improving mechanical property by crosslinking with citric acid.

Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)-citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col-CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS=60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30±5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin-eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col-CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications.

In vitro and in vivo evaluation of a novel collagen/cellulose nanocrystals scaffold for achieving the sustained release of basic fibroblast growth factor.

Tissue-engineered dermis is thought to be the best treatment for skin defects; however, slow vascularization of these biomaterial scaffolds limits their clinical application. Exogenous administration of angiogenic growth factors is highly desirable for tissue regeneration. In this study, biodegradable gelatin microspheres (GMs) containing basic fibroblast growth factor (bFGF) were fabricated and incorporated into a porous collagen/cellulose nanocrystals (CNCs) scaffold, as a platform for long-term release and consequent angiogenic boosting. The physicochemical properties of these scaffolds were examined and the in vitro release pattern of bFGF from scaffolds was measured by ELISA. Collagen/CNCs scaffolds with and without bFGF-GMs were incubated with human umbilical vein endothelial cells for 1 week, results showed that the scaffolds with bFGF-GMs significantly augmented cell proliferation. Then, four different groups of scaffolds were implanted subcutaneously into Sprague-Dawley rats to study angiogenesis in vivo via macroscopic observation, and hematoxylin and eosin and immunohistochemical staining. The results suggested that the collagen/CNCs/bFGF-GMs scaffolds had a significantly higher number of newly formed and mature blood vessels, and the fastest degradation rate. This study demonstrated that collagen/CNCs/bFGF-GMs scaffolds have great potential in skin tissue engineering.

Improving the mechanical properties of collagen-based membranes using silk fibroin for corneal tissue engineering.

Although collagen with outstanding biocompatibility has promising application in corneal tissue engineering, the mechanical properties of collagen-based scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This article describes a toughness reinforced collagen-based membrane using silk fibroin. The collagen-silk fibroin membranes based on collagen [silk fibroin (w/w) ratios of 100:5, 100:10, and 100:20] were prepared by using silk fibroin and cross-linking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These membranes were analyzed by scanning electron microscopy and their optical property, and NaCl and tryptophan diffusivity had been tested. The water content was found to be dependent on the content of silk fibroin, and CS10 membrane (loading 10 wt % of silk fibroin) performed the optimal mechanical properties. Also the suture experiments have proved CS10 has high suture retention strength, which can be sutured in rabbit eyes integrally. Moreover, the composite membrane proved good biocompatibility for the proliferation of human corneal epithelial cells in vitro. Lamellar keratoplasty shows that CS10 membrane promoted complete epithelialization in 35 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization, and keratoconus are not observed. The composite films show potential for use in the field of corneal tissue engineering.

Nanoparticles of deoxycholic acid, polyethylene glycol and folic acid-modified chitosan for targeted delivery of doxorubicin.

Chitosan (CS) was first modified hydrophobically with deoxycholic acid (DCA) and then with polyethylene glycol (PEG) to obtain a novel amphiphilic polymer (CS-DCA-PEG). This was covalently bound to folic acid (FA) to develop nanoparticles (CS-DCA-PEG-FA) with tumor cell targeting property. The structure of the conjugates was characterised using Fourier transform infrared and (1)H nuclear magnetic resonance spectroscopy and X-ray diffraction. Based on self-aggregation, the conjugates formed nanoparticles with a low critical aggregation concentration of 0.035 mg/ml. The anti-cancer drug doxorubicin (DOX) was encapsulated into the nanoparticles with a drug-loading capacity of 30.2 wt%. The mean diameter of the DOX-loaded nanoparticles was about 200 nm, with a narrow size distribution. Transmission electron microscopy images showed that the DOX-loaded nanoparticles were spherical. The drug release was studied under different conditions. Furthermore, the cytotoxic activities of DOX in CS-DCA-PEG-FA nanoparticles against folate receptor (FR)-positive HeLa cells and FR-negative fibroblast 3T3 cells were evaluated. These results suggested that the CS-DCA-PEG-FA nanoparticles may be a promising vehicle for the targeting anticancer drug to tumor cells.