Targeting DAD1 gene with CRISPR-Cas9 system transmucosally delivered by fluorinated polylysine nanoparticles for bladder cancer intravesical gene therapy.

Background: Intravesical chemotherapy is highly recommended after transurethral resection of bladder tumor for patients with bladder cancer (BCa). However, this localized adjuvant therapy has drawbacks of causing indiscriminate damage and inability to penetrate bladder mucosal. Methods: Fluorinated polylysine micelles (PLLF) were synthesized by reacting polylysine (PLL) with heptafluorobutyrate anhydride. Anti-apoptotic gene defender against cell death 1 (DAD1) was selected by different gene expression analysis between BCa patients and healthy individuals and identified by several biological function assays. The gene transfection ability of PLLF was verified by multiple in vitro and in vivo assays. The therapeutic efficiency of PLLF nanoparticles (NPs) targeting DAD1 were confirmed by intravesical administration using an orthotopic BCa mouse model. Results: Decorated with fluorinated chains, PLL can self-assemble to form NPs and condense plasmids with excellent gene transfection efficiency in vitro. Loading with the CRISPR-Cas9 system designed to target DAD1 (Cas9-sgDAD1), PLLF/Cas9-sgDAD1 NPs strongly inhibited the expression of DAD1 in BCa cells and induced BCa cell apoptosis through the MAPK signaling pathway. Furthermore, intravesical administration of PLLF/Cas9-sgDAD1 NPs resulted in significant therapeutic outcomes without systemic toxicity in vivo. Conclusion: The synthetized PLLF can transmucosally deliver the CRISPR-Cas9 system into orthotopic BCa tissues to improve intravesical instillation therapy for BCa. This work presents a new strategy for targeting DAD1 gene in the intravesical therapy for BCa with high potential for clinical applications.

An automatic texture feature analysis framework of renal tumor: surgical, pathological, and molecular evaluation based on multi-phase abdominal CT.

OBJECTIVES: To determine whether the texture feature analysis of multi-phase abdominal CT can provide a robust prediction of benign and malignant, histological subtype, pathological stage, nephrectomy risk, pathological grade, and Ki67 index in renal tumor. METHODS: A total of 1051 participants with renal tumor were split into the internal cohort (850 patients from four different hospitals) and the external testing cohort (201 patients from another local hospital). The proposed framework comprised a 3D-kidney and tumor segmentation model by 3D-UNet, a feature extractor for the regions of interest based on radiomics and image dimension reduction, and the six classifiers by XGBoost. A quantitative model interpretation method called SHAP was used to explore the contribution of each feature. RESULTS: The proposed multi-phase abdominal CT model provides robust prediction for benign and malignant, histological subtype, pathological stage, nephrectomy risk, pathological grade, and Ki67 index in the internal validation set, with the AUROC values of 0.88 ± 0.1, 0.90 ± 0.1, 0.91 ± 0.1, 0.89 ± 0.1, 0.84 ± 0.1, and 0.88 ± 0.1, respectively. The external testing set also showed impressive results, with AUROC values of 0.83 ± 0.1, 0.83 ± 0.1, 0.85 ± 0.1, 0.81 ± 0.1, 0.79 ± 0.1, and 0.81 ± 0.1, respectively. The radiomics feature including the first-order statistics, the tumor size-related morphology, and the shape-related tumor features contributed most to the model predictions. CONCLUSIONS: Automatic texture feature analysis of abdominal multi-phase CT provides reliable predictions for multi-tasks, suggesting the potential usage of clinical application. CLINICAL RELEVANCE STATEMENT: The automatic texture feature analysis framework, based on multi-phase abdominal CT, provides robust and reliable predictions for multi-tasks. These valuable insights can serve as a guiding tool for clinical diagnosis and treatment, making medical imaging an essential component in the process. KEY POINTS: • The automatic texture feature analysis framework based on multi-phase abdominal CT can provide more accurate prediction of benign and malignant, histological subtype, pathological stage, nephrectomy risk, pathological grade, and Ki67 index in renal tumor. • The quantitative decomposition of the prediction model was conducted to explore the contribution of the extracted feature. • The study involving 1051 patients from 5 medical centers, along with a heterogeneous external data testing strategy, can be seamlessly transferred to various tasks involving new datasets.

Cancer-Associated Fibroblast-Induced Remodeling of Tumor Microenvironment in Recurrent Bladder Cancer.

Bladder carcinoma (BC) recurrence is a major clinical challenge, and targeting the tumor microenvironment (TME) is a promising therapy. However, the relationship between individual TME components, particularly cancer-associated fibroblasts (CAFs), and tumor recurrence is unclear. Here, TME heterogeneity in primary and recurrent BC is investigated using single-cell RNA sequence profiling of 62 460 cells. Two cancer stem cell (CSC) subtypes are identified in recurrent BC. An inflammatory CAF subtype, ICAM1+ iCAFs, specifically associated with BC recurrence is also identified. iCAFs are found to secrete FGF2, which acts on the CD44 receptor of rCSC-M, thereby maintaining tumor stemness and epithelial-mesenchymal transition. Additionally, THBS1+ monocytes, a group of myeloid-derived suppressor cells (MDSCs), are enriched in recurrent BC and interacted with CAFs. ICAM1+ iCAFs are found to secrete CCL2, which binds to CCR2 in MDSCs. Moreover, elevated STAT3, NFKB2, VEGFA, and CTGF levels in iCAFs reshape the TME in recurrent tumors. CCL2 inhibition in an in situ BC mouse model suppressed tumor growth, decreased MDSCs and Tregs, and fostered tumor immune suppression. The study results highlight the role of iCAFs in TME cell-cell crosstalk during recurrent BC. The identification of pivotal signaling factors driving BC relapse is promising for the development of novel therapies.

Alterations in the Gut Microbiota in Pregnant Women with Pregestational Type 2 Diabetes Mellitus.

Human gut dysbiosis is associated with type 2 diabetes mellitus (T2DM); however, the gut microbiome in pregnant women with pregestational type 2 diabetes mellitus (PGDM) remains unexplored. We investigated the alterations in the gut microbiota composition in pregnant women with or without PGDM. The gut microbiota was examined using 16S rRNA sequencing data of 234 maternal fecal samples that were collected during the first (T1), second (T2), and third (T3) trimesters. The PGDM group presented a reduction in the number of gut bacteria taxonomies as the pregnancies progressed. Linear discriminant analyses revealed that Megamonas, Bacteroides, and Roseburia intestinalis were enriched in the PGDM group, whereas Bacteroides vulgatus, Faecalibacterium prausnitzii, Eubacterium rectale, Bacteroides uniformis, Eubacterium eligens, Subdoligranulum, Bacteroides fragilis, Dialister, Lachnospiraceae, Christensenellaceae R-7, Roseburia inulinivorans, Streptococcus oralis, Prevotella melaninogenica, Neisseria perflava, Bacteroides ovatus, Bacteroides caccae, Veillonella dispar, and Haemophilus parainfluenzae were overrepresented in the control group. Correlation analyses showed that the PGDM-enriched taxa were correlated with higher blood glucose levels during pregnancy, whereas the taxonomic biomarkers of normoglycemic pregnancies exhibited negative correlations with glycemic traits. The microbial networks in the PGDM group comprised weaker microbial interactions than those in the control group. Our study reveals the distinct characteristics of the gut microbiota composition based on gestational ages between normoglycemic and PGDM pregnancies. Further longitudinal research involving women with T2DM at preconception stages and investigations using shotgun metagenomic sequencing should be performed to elucidate the relationships between specific bacterial functions and PGDM metabolic statuses during pregnancy and to identify potential therapeutic targets. IMPORTANCE The incidence of pregestational type 2 diabetes mellitus (PGDM) is increasing, with high rates of serious adverse maternal and neonatal outcomes that are strongly correlated with hyperglycemia. Recent studies have shown that type 2 diabetes mellitus is associated with gut microbial dysbiosis; however, the gut microbiome composition and its associations with the metabolic features of patients with PGDM remain largely unknown. In this study, we investigated the changes in the gut microbiota composition in pregnant women with and without PGDM. We identified differential taxa that may be correlated with maternal metabolic statuses during pregnancy. Additionally, we observed that the number of taxonomic and microbial networks of gut bacteria were distinctly reduced in women with hyperglycemia as their pregnancies progressed. These results extend our understanding of the associations between the gut microbial composition, PGDM-related metabolic changes, and pregnancy outcomes.

Prognostic Significance of Lineage Diversity in Bladder Cancer Revealed by Single-Cell Sequencing.

Bladder cancer is the most common malignant tumor of the urinary system. We investigated the clinical implications of cell lineages in bladder cancer by integrating single-cell and bulk transcriptome data. By investigating the single-cell transcriptional profiles of 12,424 cells from normal bladder, eleven cell types and five types of epithelial sub-population were identified. Based on the signature of cell types identified in single-cell profiles, deconvolution analysis was employed to estimate cell types and epithelial lineages in the bulk RNA sequencing bladder cancer cohort. Cancer subtypes with clinical implications were further identified based on the heterogeneity of the epithelial lineage across patients. This study suggests that the EMT-like subtype is robustly correlated with poor prognosis and the umbrella subtype is a positive factor for the patient survival. Our research has a high potential for accurate prognostic and therapeutic stratification of bladder cancer.

A genome-wide association study for gut metagenome in Chinese adults illuminates complex diseases.

The gut microbiome has been established as a key environmental factor to health. Genetic influences on the gut microbiome have been reported, yet, doubts remain as to the significance of genetic associations. Here, we provide shotgun data for whole genome and whole metagenome from a Chinese cohort, identifying no <20% genetic contribution to the gut microbiota. Using common variants-, rare variants-, and copy number variations-based association analyses, we identified abundant signals associated with the gut microbiome especially in metabolic, neurological, and immunological functions. The controversial concept of enterotypes may have a genetic attribute, with the top two loci explaining 11% of the Prevotella-Bacteroides variances. Stratification according to gender led to the identification of differential associations in males and females. Our two-stage metagenome genome-wide association studies on a total of 1295 individuals unequivocally illustrates that neither microbiome nor GWAS studies could overlook one another in our quest for a better understanding of human health and diseases.

The Baseline Gut Microbiota Directs Dieting-Induced Weight Loss Trajectories.

BACKGROUND & AIMS: Elucidating key factors affecting personal responses to food is the first step toward implementing personalized nutrition strategies in for example weight loss programs. Here, we aimed to identify factors of importance for individual weight loss trajectories in a natural setting where participants were provided dietary advice but otherwise asked to self-manage the daily caloric intake and data reporting. METHODS: A 6-month weight-reduction program with longitudinal collection of dietary, physical activity, body weight, and fecal microbiome data as well as single-nucleotide polymorphism genotypes in 83 participants was conducted, followed by integration of the high-dimensional data to define the most determining factors for weight loss in a dietician-guided, smartphone-assisted dieting program. RESULTS: The baseline gut microbiota was found to outperform other factors as a predieting predictor of individual weight loss trajectories. Weight loss was also linked to the magnitude of changes in abundances of certain bacterial species during dieting. Ruminococcus gnavus (MGS0160) was significantly enriched in obese individuals and decreased during weight loss. Akkermansia muciniphila (MGS0120) and Alistipes obesi (MGS0342) were significantly enriched in lean individuals, and their abundance increased during dieting. Finally, Blautia wexlerae (MGS0575) and Bacteroides dorei (MGS0187) were the strongest predictors for weight loss when present in high abundance at baseline. CONCLUSION: Altogether, the baseline gut microbiota was found to excel as a central personal factor in capturing the relationship between dietary factors and weight loss among individuals on a dieting program.

Multi-Omics Characterization of Tumor Microenvironment Heterogeneity and Immunotherapy Resistance Through Cell States-Based Subtyping in Bladder Cancer.

Due to the strong heterogeneity of bladder cancer (BC), there is often substantial variation in the prognosis and efficiency of immunotherapy among BC patients. For the precision treatment and assessment of prognosis, the subtyping of BC plays a critical role. Despite various subtyping methods proposed previously, most of them are based on a limited number of molecules, and none of them is developed on the basis of cell states. In this study, we construct a single-cell atlas by integrating single cell RNA-seq, RNA microarray, and bulk RNA-seq data to identify the absolute proportion of 22 different cell states in BC, including immune and nonimmune cell states derived from tumor tissues. To explore the heterogeneity of BC, BC was identified into four different subtypes in multiple cohorts using an improved consensus clustering algorithm based on cell states. Among the four subtypes, C1 had median prognosis and best overall response rate (ORR), which characterized an immunosuppressive tumor microenvironment. C2 was enriched in epithelial-mesenchymal transition/invasion, angiogenesis, immunosuppression, and immune exhaustion. Surely, C2 performed the worst in prognosis and ORR. C3 with worse ORR than C2 was enriched in angiogenesis and almost nonimmune exhaustion. Displaying an immune effective environment, C4 performed the best in prognosis and ORR. We found that patients with just an immunosuppressive environment are suitable for immunotherapy, but patients with an immunosuppressive environment accompanied by immune exhaustion or angiogenesis may resist immunotherapy. Furthermore, we conducted exploration into the heterogeneity of the transcriptome, mutational profiles, and somatic copy-number alterations in four subtypes, which could explain the significant differences related to cell states in prognosis and ORR. We also found that PD-1 in immune and tumor cells could both influence ORR in BC. The level of TGFß in a cell state can be opposite to the overall level in the tissues, and the level in a specific cell state could predict ORR more accurately. Thus, our work furthers the understanding of heterogeneity and immunotherapy resistance in BC, which is expected to assist clinical practice and serve as a supplement to the current subtyping method from a novel perspective of cell states.

Alterations in the human gut microbiome associated with Helicobacter pylori infection.

Helicobacter pylori infection (HPI) is a prevalent infectious disease associated with gastric ulcer, gastric cancer, and many nongastrointestinal disorders. To identify genes that may serve as microbial markers for HPI, we performed shotgun metagenomic sequencing of fecal samples from 313 Chinese volunteers who had undergone a C14 breath test. Through comparing differences in intestinal microbial community structure between H. pylori-positive and H. pylori-negative individuals, we identified 58 HPI-associated microbial species (P < 0.05, Wilcoxon test). A classifier based on microbial species markers showed high diagnostic ability for HPI (AUC = 0.84). Furthermore, levels of gut microbial vitamin B12 (VB12) biosynthesis and plasma VB12 were significantly lower in H. pylori-positive individuals compared with H. pylori-negative individuals (P < 0.05, Wilcoxon test). This study reveals that certain alterations in gut microbial species and functions are associated with HPI and shows that gut microbial shift in HPI patients may indirectly elevate the risk of VB12 deficiency.

Impact of early events and lifestyle on the gut microbiota and metabolic phenotypes in young school-age children.

BACKGROUND: The gut microbiota evolves from birth and is in early life influenced by events such as birth mode, type of infant feeding, and maternal and infant antibiotics use. However, we still have a gap in our understanding of gut microbiota development in older children, and to what extent early events and pre-school lifestyle modulate the composition of the gut microbiota, and how this impinges on whole body metabolic regulation in school-age children. RESULTS: Taking advantage of the KOALA Birth Cohort Study, a long-term prospective birth cohort in the Netherlands with extensive collection of high-quality host metadata, we applied shotgun metagenomics sequencing and systematically investigated the gut microbiota of children at 6-9 years of age. We demonstrated an overall adult-like gut microbiota in the 281 Dutch school-age children and identified 3 enterotypes dominated by the genera Bacteroides, Prevotella, and Bifidobacterium, respectively. Importantly, we found that breastfeeding duration in early life and pre-school dietary lifestyle correlated with the composition and functional competences of the gut microbiota in the children at school age. The correlations between pre-school dietary lifestyle and metabolic phenotypes exhibited a striking enterotype dependency. Thus, an inverse correlation between high dietary fiber consumption and low plasma insulin levels was only observed in individuals with the Bacteroides and Prevotella enterotypes, but not in Bifidobacterium enterotype individuals in whom the gut microbiota displayed overall lower microbial gene richness, alpha-diversity, functional potential for complex carbohydrate fermentation, and butyrate and succinate production. High total fat consumption and elevated plasma free fatty acid levels in the Bifidobacterium enterotype are associated with the co-occurrence of Streptococcus. CONCLUSIONS: Our work highlights the persistent effects of breastfeeding duration and pre-school dietary lifestyle in affecting the gut microbiota in school-age children and reveals distinct compositional and functional potential in children according to enterotypes. The findings underscore enterotype-specific links between the host metabolic phenotypes and dietary patterns, emphasizing the importance of microbiome-based stratification when investigating metabolic responses to diets. Future diet intervention studies are clearly warranted to examine gut microbe-diet-host relationships to promote knowledge-based recommendations in relation to improving metabolic health in children.

Naproxen Nanoparticle-Loaded Thermosensitive Chitosan Hydrogel for Prevention of Postoperative Adhesions.

Postoperative adhesions are the most common complications of peri-abdominal surgery; they not only affect the patient's quality of life but also increase the risk of a subsequent surgery. The use of implantable dressings to physically block surgical wounds is the primary solution to prevent postoperative adhesions. In this study, we prepared naproxen nanoparticles that were loaded with chitosan hydrogel (CS/Nap hydrogel) to prevent postoperative adhesions. Our data confirmed that the prepared CS/Nap hydrogel was thermosensitive and suitable for injection. The efficacy of anti-adhesion in a rat model revealed that the hydrogel effectively separated from the wounds of the abdominal wall and cecum. On day 7 postsurgery, the wounds were completely covered by a new epithelial layer, whereas wounds in the negative control group were glued together. Additionally, the in vivo toxicity study showed that the CS/Nap hydrogel had fewer toxic and side effects on major tissues and organs, including the liver, spleen, heart, lung, and kidney. We showed that a drug delivery system based on CS/Nap hydrogel has the potential not only to prevent postoperative abdominal adhesions and relieve pain but also to contribute to the administration of the hydrophobic drug naproxen.

Cognitive Impairment Due to Leptin Withdrawal in Rat Offspring of Dams with Maternal Diet-Induced Obesity.

BACKGROUND Obesity during pregnancy is a potential threat to the health and neurodevelopment of the offspring. This study investigated the effect of maternal diet-induced obesity (DIO) on the cognitive abilities of the offspring in rats. MATERIAL AND METHODS Female Sprague-Dawley rats were fed a high-fat diet to induce obesity, and the leptin levels in dams and offspring were evaluated using ELISA. The effect of DIO on the learning and memory in offspring was measured using electrophysiology and the Morris water maze test. In addition, the expression of molecules related to synaptic plasticity was investigated. Furthermore, the effect of leptin on neuronal cells was investigated, and the influence of leptin on the regulation of calcium current activity was evaluated in vitro. RESULTS Results showed that DIO dams had increased leptin levels during gestation, and offspring had drastically decreased leptin levels after delivery. The cognitive ability of offspring with maternal DIO was mildly impaired after delivery. Furthermore, long-term potentiation in DIO neonatal offspring was lower than in the control group at 2-3 weeks old; decreased expression of the leptin receptor was accompanied by N-methyl-D-aspartate receptor (NMDAR) downregulation during neonatal development. In addition, it was demonstrated that leptin enhanced NMDAR activity and promoted calcium current activity in a concentration-dependent manner. CONCLUSIONS The results indicated that the neonatal offspring of DIO dams showed cognitive impairment during neonatal development, which may be attributed to leptin withdrawal.

Preparation of Bone Marrow Mesenchymal Stem Cells Combined with Hydroxyapatite/Poly(d,l-lactide) Porous Microspheres for Bone Regeneration in Calvarial Defects.

A novel three-dimensional biomimetic porous microsphere was successfully designed in this study, which was composed of PDLLA, bone marrow mesenchymal stem cells (MSCs), and nanohydroxyapatite (nHAp). nHAp/PDLLA/MSC porous microspheres that are supposed to be a significant constituent of bone in vertebrate were prepared to act as biodegradable support materials. In addition, bone MSCs act as seeding cells in bone defect repair. The microstructure of the obtained nHAp/PDLLA/MSC porous microspheres was characterized. Scanning electronic microscopy showed that the composite materials exhibited a cross-linked porous structure. In vivo biocompatibility was studied by the way of implanting the nHAp/PDLLA porous microspheres subcutaneously in rats for 4 and 8 weeks. In addition, the osteogenic capacity of the nHAp/PDLLA/MSC porous microspheres was assessed by implanting the 10 mm × 10 mm × 3 mm cranial defect of New Zealand white rabbits. In vivo studies confirmed that nHAp/PDLLA/MSC porous microspheres had a good biocompatibility and were better in inducing bone regeneration than nHAp/PDLLA porous microspheres and the self-healing process. All of the results suggested that the nHAp/PDLLA/MSC porous microspheres present a remarkable potential in calvarial defect repair and bone tissue engineering.

Preparation and therapeutic application of docetaxel-loaded poly(d,l-lactide) nanofibers in preventing breast cancer recurrence.

The aim of this study was to develop docetaxel (DTX)-loaded poly-d,l-lactide (PDLLA) nanofibers and evaluate their therapeutic effect in preventing local breast cancer recurrence. DTX was incorporated into biodegradable PDLLA nanofibers by electrospinning. The surface morphology of the DTX/PDLLA nanofibers was characterized using scanning electron microscopy and wide angle X-ray diffraction. The in vitro release behavior of DTX from the fiber mats was also studied in detail. The cytotoxicity of DTX/PDLLA nanofibers was evaluated by MTT assay in 4T1 breast cancer cells. Flow cytometry revealed that DTX/PDLLA nanofibers exhibited apoptotic activity in 4T1 cells. In vivo antitumor efficacy of DTX/PDLLA nanofibers was evaluated in BALB/c mice bearing local breast tumors. Locoregional recurrence after primary tumor resection decreased obviously in mice treated with subcutaneously (16.7%) administered DTX-loaded PDLLA nanofibers, compared with the blank PDLLA nanofibers (88.9%), systemic (75.0%) or locally (77.8%) administered DTX and the control group (100%) (p < 0.05). Finally, after subcutaneous transplantation in mice, the DTX/PDLLA scaffolds presented excellent biocompatibility, as exhibited by the minimal presence of inflammatory cells in the region surrounding the scaffolds. Our results suggest that DTX/PDLLA nanofibers could have great potential for clinical application requiring local chemotherapy.

Dexamethasone-loaded poly(D, L-lactic acid) microspheres/poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) micelles composite for skin augmentation.

Soft tissue augmentation using various injectable fillers has gained popularity as more patients seek esthetic improvement through minimally invasive procedures requiring little or no recovery time. The currently available injectable skin fillers can be divided into three categories. With careful assessment, stimulatory fillers are the most ideal fillers. In this study, dexamethasone-loaded poly(D, L-lactic acid) (PLA) microspheres of approximately 90 micro m suspended in poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) micelles were prepared as stimulatory filler for skin augmentation. The biodegradable PECE copolymer can form nano-sized micelles in water, which instantly turns into a non-flowing gel at body temperature due to micellar aggregation. The PECE micelles (making up 90% of composite) served as vehicle for subcutaneous injection were metabolized within 44 days. At the same time, the dexamethasone-loaded PLA microspheres (10% of composite) merely served as stimulus for connective tissue formation. Dexamethasone-loaded PLA microspheres/PECE micelles composite presented great hemocompatibility in vitro. It was demonstrated in the in vive study that the composite was biodegradable, biocompatible, nontoxic and nonmigratory. Histopathological studies indicated that the composite could stimulate collagen regeneration. Furthermore, granuloma, the main complication of the stimulatory fillers, did not appear when the composite was injected into the back of SD rats, because of the dexamethasone controlled release from the composite. All results suggested that dexamethasone-loaded PLA microspheres/PECE micelles composite may be an efficient and promising biomaterial for skin augmentation.

Preparation of curcumin-loaded poly(ester amine) nanoparticles for the treatment of anti-angiogenesis.

The aim of this study was to prepare curcumin loaded poly(ester amine) nanoparticles and enhance their hydrophilicity and treatment efficacy on anti-angiogenesis zebra fish model. Poly(ester amine) (PEA) copolymer was synthesized in this study. The curcumin-loaded PEA nanoparticles were prepared through double emulsion-solvent evaporation technique. The average particle size of obtained nanoparticles was about 100 nm. The zeta potential of prepared nanoparticles was about 35.8+/-2.4 mV. Transmission electron microscopy demonstrated a narrow size distribution with in vitro release profile demonstrating in vitro slow release of curcumin from the PEA nanoparticles. The in vitro cytotoxicity of the curcumin encapsulated PEA nanoparticles nearly had the same tendency of cytotoxic activity in vitro with free curcumin on tumor cells. In vitro cellular uptake of the curcumin-loaded nanoparticles demonstrated in Hela cells demonstrated that this kind of nanoparticles can be a promising candidate as a drug delivery system to cancer cells. The Cur/PEA nanoparticles more efficiently inhibited angiogenesis (in vivo) in transgenic zebra fish model and Alginate-encapsulated tumor cells than free curcumin. No mortality or significant lesions were observed from histopathological study of the major organs. From our results, we can conclude that the prepared PEA nanoparticles are an efficient curcumin drug delivery system for anti-angiogenesis therapy.

Recent developments in scaffold-guided cartilage tissue regeneration.

Articular cartilage repair is one of the most challenging problems in biomedical engineering because the regenerative capacity of cartilage is intrinsically poor. The lack of efficient treatment modalities motivates researches into cartilage tissue engineering such as combing cells, scaffolds and growth factors. In this review we summarize the current developments on scaffold systems available for cartilage tissue engineering. The factors that are critical to successfully design an ideal scaffold for cartilage regeneration were discussed. Then we present examples of selected material types (natural polymers and synthetic polymers) and fabricated forms of the scaffolds (three-dimensional scaffolds, micro- or nanoparticles, and their composites). In the end of review, we conclude with an overview of the ways in which biomedical nanotechnology is widely applied in cartilage tissue engineering, especially in the design of composite scaffolds. This review attempts to provide recommendations on the combination of qualities that would produce the ideal scaffold system for cartilage tissue engineering.

Injectable thermosensitive PEG-PCL-PEG hydrogel/acellular bone matrix composite for bone regeneration in cranial defects.

We have certified that the injectable thermosensitive ABM/PECE composite presented promising potential in bone regeneration benefited from the incorporation of the intrinsic osteoinductive acellular bone matrix (ABM) granules into the poly(ethylene glycol)-poly(ε-capro-lactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) hydrogel. In this study, the 12 mm × 8 mm × 2 mm cranial defects of the New Zealand white rabbits were fabricated to evaluate the bone regeneration effect. The ABM/PECE composite was injected into the defect while the pure PECE as control, and the bone regeneration was evaluated at 4, 12 and 20 weeks post-surgery by X-radiological examination, micro-computed tomography examination and histological analysis. In ABM/PECE composite treated group, the new bone formed originally from both the margin and the center of the defect, and the defect region had healed up to 20 weeks. Furthermore, the shadow density of the newly formed bone eventually approximated to host cortical bone. In comparison, the control group was filled with sparing new bone with low-density only from the periphery of the defect. Meanwhile, the quantitative determination of new bone by histomorphometry confirmed the excellent bone regeneration of ABM/PECE composite. All the results suggested that the ABM/PECE composite presented enhanced bone regeneration guidance in rabbit cranial defects.

Preparation and characterization of poly(pluronic-co-L-lactide) nanofibers for tissue engineering.

In this work, a new kind of biodegradable poly(pluronic-co-L-lactide) (Pluronic-PLLA copolymers) was successfully prepared by melt-polycondensation method from L-lactide, Pluronic and isophorone diisocyanate (IPDI). The obtained copolymers were characterized by (1)H NMR, FT-IR, X-ray, and TGA/DTA. Meanwhile, three-dimensional (3-D) porous scaffolds based on Pluronic-PLLA were prepared by the electrospinning method, the factors of concentration, flow rate and voltage that influence the formation of the Pluronic-PLLA nanofibers were studied and the structure of Pluronic-PLLA nanofibers were investigated by scanning electron microscopy (SEM). MTT results revealed that the Pluronic-PLLA scaffolds had good biocompatibility and nontoxicity. Morphological study using fluorescence micrographs and scanning electron microscopy showed that in vitro osteoblast cell culture demonstrated the electrospun Pluronic-PLLA composite scaffolds could provide a suitable environment for good cell attachment. These results suggested that such Pluronic-PLLA nanofibers membranes might have prospective applications in tissue engineering field.