Background::Pancreatic ductal adenocarcinoma (PDAC) is one of the main types of malignant tumor of the digestive system, and patient prognosis is affected by difficulties in early diagnosis, poor treatment response, and a high postoperative recurrence rate. Carbohydrate antigen 19-9 (CA19-9) has been widely used as a biomarker for the diagnosis and postoperative follow-up of PDAC patients. Nevertheless, the production mechanism and potential role of CA19-9 in PDAC progression have not yet been elucidated.Methods::We performed single-cell RNA sequencing on six samples pathologically diagnosed as PDAC (three CA19-9-positive and three CA19-9-negative PDAC samples) and two paracarcinoma samples. We also downloaded and integrated PDAC samples (each from three CA19-9-positive and CA19-9-negative patients) from an online database. The dynamics of the proportion and potential function of each cell type were verified through immunofluorescence. Moreover, we built an in vitro coculture cellular model to confirm the potential function of CA19-9. Results::Three subtypes of cancer cells with a high ability to produce CA19-9 were identified by the markers TOP2A, AQP5, and MUC5AC. CA19-9 production bypass was discovered on antigen-presenting cancer-associated fibroblasts (apCAFs). Importantly, the proportion of immature ficolin-1 positive (FCN1+) macrophages was high in the CA19-9-negative group, and the proportion of mature M2-like macrophages was high in the CA19-9-positive group. High proportions of these two macrophage subtypes were associated with an unfavourable clinical prognosis. Further experiments indicated that CA19-9 could facilitate the transformation of M0 macrophages into M2 macrophages in the tumor microenvironment. Conclusions::Our study described CA19-9 production at single-cell resolution and the dynamics of the immune atlas in CA19-9-positive and CA19-9-negative PDAC. CA19-9 could promote M2 polarization of macrophage in the pancreatic tumor microenvironment.

The sacrum is a common site of stress injury. The occurrence of pressure ulcers not only leads to the aggravation of the patient′s condition, the prolongation of hospital stay, the increase of medical costs, the decline of life quality, but also aggravates the burden of society, family and medical staff. Early reasonable and effective application of sacral dressing can prevent the occurrence of pressure injury. In this study, the characteristics and effectiveness of different types of sacral dressings were reviewed by reviewing relevant literatures at home and abroad and summarizing the existing relevant studies, so as to provide guidance for clinical application.

The current problems with corneal transplant,including shortage of donors and immune rejection,could be effectively solved by constructing cornea in vitro with tissue engineering techniques,in which the selection of suitable scaffold materials is especially critical.Chitosan and its derivatives are natural biomaterials with excellent biocompatibility,biodegradability,mechanical property and plasticity,indicating wide application prospects in corneal tissue engineering.This article systematically reviews the research advances in chitosan and its derivatives in corneal tissue engineering,and the existing problems are also highlighted in order to provide theoretical basis for further clinical research.

Objective To determine the antimicrobial effects of carboxymethyl chitosan zinc (CMC-Zn +) and CMC-Zn +-peptide (CMC-Zn +-P) on four kinds of periodontal pathogens.Methods Dilution method was used to determine the minimum inhibitory concentration(MIC) of CMC-Zn + for Porphyromonas gingivalis(Pg),Actinobacillusactinomycetemcomitans(Aa),Prevotella intermedia(Pi) and Actinomyces viscosus(Av).The antimicrobial characters of CMC-Zn+ and CMC-Zn+-P on these four kinds of pathogens were evaluated by disk diffusion method.Results The MIC of CMC-Zn+ for Pg,Aa,Pi and Av was 0.312 5％,0.156 25％,0.156 25％ and 0.078 125％ respectively.Significant antimicrobial effects were improved along with the increased concentration of CMC-Zn+ and CMC-Zn+-P(P＜0.01),while the best antimicrobial concentrations of both CMC-Zn+ and CMC-Zn+-P were 5％.The antimicrobial effect of CMC-Zn+-P was better than that of CMC-Zn+ on the same kind of periodontal pathogen(P＜0.01).CMC-Zn+-P showed different antimicrobial effects on the four periodontal pathogens(Av＞Aa＞Pi or Av＞Aa＞Pg,P＜0.01).Conclusions CMC-Zn + and CMC-Zn +-P have inhibition effect on Pg,Aa,Pi and Av,and the best antibacterial concentration was 5％.The CMC-Zn+-P has better antibacterial effect than CMC-Zn+ on Pg,Aa,Pi and Av.

BACKGROUND: Carboxymethyl chitosan is a water-soluble derivate modified from chitosan, with various biological activities. It is a good ligand of metal ion and can integrate Ca~(2+) to prepare a novel biological material. OBJECTIVE: To explore a method for preparing carboxymethyl chitosan calcium (CCC) and analyze its properties and structure. METHODS: CCC was produced by carboxymethyl ohitosan reacting with solution of calcium chloride. The solubility, carboxymethylation degree, rotational viscosity, and calcium content of CCC were determined, and infrared and ultraviolet spectral analyses were performed.RESULTS AND CONCLUSION: The calcium content of CCC was approximately 15%. Compared with carboxymethyl chitosan, infrared spectrum and ultraviolet spectrum of CCC were changed. The prepared CCC is a new calcium compound through property and structural analysis.

Objective To discuss the feasibility of Shuyisha as hemostasis and repair material for liver wound. Methods Hemolysis rate, acute toxicity and eytotoxicity of Shuyisha were measured. A hemorrhage model was established by making an open wound (5 mm× 3 nun ×2 mm) on the left liver lobe of mice. Hemostasis was performed with Shuyisha in experimental group and with Surgicel in control group, when the hemostatic time and total blood loss (TBL) were accurately recorded and regular macro-scopic and histological observation carried out. Results The hemolysis rate of Shuyisha was 2.33%, with maximum tolerance does of over 0.48 g/kg and the eytotoxicity at zero. The hemostatie time of Shuy-isha was (5.00 ±0.00) s, with total blood loss of (0.88±0.18) g/kg, better than Surgicel (P< 0.05). Shuyisha was degraded completely within 14 days, with the wound healed within 21 days in ex-perimental group, much better than Surgieel. Conclusions The hemolysis rate, acute toxicity and cy-totoxicity of Shuyisha are up to the requirement of biomedical materials. Shuyisha has effective hemosta-sis, which may be related to its molecular structure and adhesion.

To study the possibility of using hydroxypropyl chitosan-based blend membranes as carriers of corneal cells in tissue engineering, we prepared three kinds of blend membranes labeled hydroxypropyl chitosan/chondroitin sulfate, hydroxypropyl chitosan/gelatin/chondroitin sulfate and hydroxypropyl chitosan/oxidized hyaluronic acid/chondroitin sulfate. The transparency, water content and ability of protein adsorption of the blend membranes were measured. To evaluate the cytocompatibility of the blend membranes with corneal epithelial cells, rabbit corneal epithelial cells were cultured on the surface of the carrier membranes. The morphological characteristics, cell adhesion, cell proliferation and the activity of lactate dehydrogenase (LDH) in the media were investigated. Three kinds of blend membranes had good optical transmittance, suitable water content and ability of protein adsorption. The results showed that the less injury was made to corneal epithelial cells by the hydroxypropyl chitosan/gelatin/chondroitin sulfate blend membrane than the others. This kind of membrane was favor of the growth and adhesion of corneal epithelial cells. The hydroxypropyl chitosan/gelatin/chondroitin sulfate blend membrane is a promising carrier of corneal cells and can be used in reconstruction of tissue engineered cornea.
Animals ; Biocompatible Materials ; chemistry ; pharmacology ; Cell Culture Techniques ; methods ; Cell Proliferation ; drug effects ; Cells, Cultured ; Chitosan ; chemistry ; Chondroitin Sulfates ; chemistry ; Epithelium, Corneal ; cytology ; Gelatin ; chemistry ; Membranes, Artificial ; Rabbits ; Tissue Engineering ; methods

Effects of carboxymethyl-chitosan (CM-Chitosan) with different molecular weight on the proliferation of skin fibroblasts and keratinocytes were examined in vitro; bFGF and EGF, as controls, were seperately used for comparison. Chitosan with different molecular weight was prepared by acid degradation and oxidation degradation; CM-Chitosan with different molecular weight was synthesized from corresponding Chitosan. Microscopy and MTT method were applied to evaluate the different effects. The results demonstrated that CM-Chitosan with different molecular weight promoted the proliferation of skin fibroblasts and keratinocytes at 1-1000 ppm, and the concentration at 100 ppm had the strongest effects. The effects of low molecular weight CM-Chitosan were greater than those of high molecular weight CM-Chitosan. CM-Chitosan (Mn= 3KD) had the strongest promotive effects on skin fibroblasts and keratinocytes; it had equivalent effects when compared with bFGF and EGF.
Animals ; Cell Proliferation ; drug effects ; Cells, Cultured ; Chitosan ; analogs & derivatives ; chemical synthesis ; pharmacology ; Fibroblasts ; cytology ; drug effects ; Humans ; Keratinocytes ; cytology ; drug effects ; Mice ; Molecular Weight ; Skin ; cytology

OBJECTIVE: Osteoblasts are essential for osteogenesis and bone metabolism, the in vitro culture of osteoblasts is the foundation for studies on bone metabolism and osteogenetic mechanism. Therefore, it is of great significance to study the related factors affecting it.DATA SOURCES: Related literature about the influencing factors of in vitro culture of osteoblasts were searched for in Medline from January 1980 to December 2004 with retrieval words of "osteoblasts, culture in vitro, in fluencing factors", with the language limited to English. Meanwhile, it was also searched in the CBM between January 1995 and December 2004 with the retrieval words of "osteoblasts, in vitro culture, influencing factors",with the language of the articles limited to Chinese.STUDY SELECTION: After preliminary examination, literature that met the need of this study was searched for the full text. Inclusion criteria: Factors influencing the in vitro culture of osteoblasts included ① physical factors; ② microelements; ③ growth factors; and ④ hormones.Reviews were removed from this study because of summary or repetitive research.DATA EXTRACTION: A total of 105 articles related to the influencing factors of the in vitrocul ture of osteoblasts were obtained, articles of repetitive and similar researchwere removed; thereby 17 articles were included in the study.DATA SYNTHESIS: ① Physical factors: Ionizing radiation, microgravity,external force, and oxygen pressure. ② Microelements: microelement deficiency would hinder the skeletal growth, or even lead to malformation. Osteoblastic proliferation is closely related to some microelements, mainly including zinc, aluminum, fluorine, copper, manganese, calcium, and magnesium. ③ Growth factors closely related to osteogenesis mainly consist of bone morphogenetic protein, platelet-derived growth factor, fibroblast growth factor, transforming growth factor-beta, insulin like growth factor,and osteogenic growth peptide (OGP). ④ Hormones capable of promoting the proliferation and differentiation are growth hormone, estrogen, thyroxine, parathyroxine, and glucocorticosteroid.CONCLUSION: Multiple factors are involved in the in vitro culture of osteoblasts. It is helpful to understand these influencing factors to seek an effective way for the in vitro culture ofosteoblasts that is applied in tissue engineering.

Some different membranes were prepared by Chitosan with the degree of deacetylation (DD) of 63.7%, 73.7%, 83% and 97% respectively. To study the biocompatibility of Chitosan membrane toward corneal stromal cells, the rabbit cells were cultured on the surface of different DD chitosan membranes. The morphological characteristics, the cell-adhesion, the cell proliferation and the activity of LDH in the medium were investigated. The results of experiment shows that the DD of Chitosan has very significant effect on the biocompatibility of Chitosan membrane toward corneal stromal cells. The more DD of Chitosan, the less injury was made to corneal stromal cells by the chitosan membrane, which is favor of the growing and adhesion of corneal stromal cells. The biocompatibility of the membrane made with low DD Chitosan with corneal stromal cells became worse.
Acetylation ; Animals ; Biocompatible Materials ; chemistry ; pharmacology ; Cell Adhesion ; drug effects ; Cell Division ; drug effects ; Chitosan ; chemistry ; pharmacology ; Cornea ; cytology ; Materials Testing ; Membranes, Artificial ; Rabbits ; Stromal Cells ; drug effects