The biocompatible hydrogel was fabricated under suitable conditions with natural dextran and polyethylene glycol (PEG) as the reaction materials. The oligomer (Dex-AI) was firstly synthesized with dextran and allylisocyanate (AI). This Dex-AI was then reacted with poly (ethyleneglycoldiacrylate) (PEGDA) under the mass ratio of 4∶6 to get hydrogel (DP) with the maximum water absorption of 810%. This hydrogel was grafted onto the surface of medical catheter via diphenyl ketone treatment under ultraviolet (UV) initiator. The surface contact angle became lower from (97 ± 6.1)° to (25 ± 4.2)° after the catheter surface was grafted with hydrogel DP, which suggests that the catheter possesses super hydrophilicity with hydrogel grafting. The evaluation after they were implanted into ICR rats subcutaneously verified that this catheter had less serious inflammation and possessed better histocompatibility comparing with the untreated medical catheter. Therefore, it could be concluded that hydrogel grafting is a good technology for patients to reduce inflammation due to catheter implantation, esp. for the case of retention in body for a relative long time.
Allyl Compounds ; Animals ; Biocompatible Materials ; Catheters ; Dextrans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; Hydrogels ; Hydrophobic and Hydrophilic Interactions ; Isocyanates ; Polyethylene Glycols ; Rats ; Water

OBJECTIVETo evaluate the biocompatibility and viability of nonionic triblock copolymer Pluronic F-127 as a cell scaffold for osteogenic differentiation of dental pulp stem cells(DPSC).

METHODSDPSC were obtained via enzymatic digestion method and purified bylimited dilution method. The freeze dried hydrogel of 20% Pluronic F-127 was prepared and itsstructurewas observed usingscanning electron microscopy(SEM). After the encapsulation of cells of passage 3 in Pluronic F-127, the effects of hydrogel on the proliferations of DPSC were assessed with methyl thiazolyl terazolium(MTT) after one day and 3, 5, 7 days of incubations, respectively. On day 14, osteogenic abilities of DPSC encapsulated in the hydrogel were estimated by means of alizarin red S, immunocytochemical staining and real-time quantitative PCR(RT-qPCR).

RESULTSDPSC were isolated and cultured successfully in the present study. SEM observations showed that porous structures which might be suitable for cell culture. A570 values of MTT were then normalized. A570 values of the cells in 2D cultures were 0.30±0.06, 0.30±0.17, 0.35±0.04 and 0.25±0.06 and A570 values of DPSC in 3D cultures were 0.36±0.06, 0.54±0.18, 0.70±0.10 and 0.32±0.10 on day 1, 3, 5 and 7, respectively. A570 value peaks were found on day 5 in both groups. The proliferation of 3D cultured DPSC was higher than that of 2D cultured cells(P<0.05). After 14 days of osteogenic induction, there were no calcium nodules observed in the control group and the numbers of calcium nodulesin the 2D and 3D groups had no significant difference(P>0.05). Inmmunocytochemical staining demonstrated strong expression of osteoblast marker Runt-related transcription factor 2(RUNX2), type Ⅰ collagen(Col-Ⅰ) and relatively low expression of osteocalcin(OCN). Moreover, RT-qPCR showed no differences between the relative expression of ALP, RUNX-2, OCN in the 2D and 3D groups (P>0.05), but a higher relative expression of Col-Ⅰ was observed in the 3D group(P=0.023).

CONCLUSIONSPluronic F-127 is a promising cell scaffold or cell carrier for the osteobalst differentiation of dental pulp stem cells.

Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Collagen Type I ; metabolism ; Core Binding Factor Alpha 1 Subunit ; metabolism ; Dental Pulp ; cytology ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; Osteoblasts ; metabolism ; Osteocalcin ; metabolism ; Osteogenesis ; Poloxamer ; Stem Cells ; cytology ; Tissue Scaffolds

OBJECTIVEAlthough chondroprotective activities have been documented for polysaccharides, the potential target of different polysaccharide may differ. The study was aimed to explore the effect of glucan HBP-A in chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs in vivo, especially on the expression of type II collagen.

METHODSChondrocytes isolated from rabbit articular cartilage were cultured and verified by immunocytochemical staining of type II collagen. Chondrocyte viability was assessed after being treated with HBP-A in different concentrations. Morphological status of chondrocytes-alginate hydrogel constructs in vitro was observed by scanning electron microscope (SEM). The constructs were treated with HBP-A and then injected to nude mice subcutaneously. Six weeks after transplantation, the specimens were observed through transmission electron microscopy (TEM). The mRNA expressions of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTs-5), aggrecan and type II collagen in both monolayer culture and constructs were determined by real time polymerase chain reaction (PCR). The expression of type II collagen and matrix metalloproteinases-3 (MMP-3) in chondrocyte monolayer culture was also tested through Western blot and enzyme linked immunosorbent assay (ELISA), respectively.

RESULTSMMP-3 secretion and ADAMTs-5 mRNA expression in vitro were inhibited by HBP-A at 0.3 mg/mL concentration. In morphological study, there were significant appearance of collagen in those constructs treated by HBP-A. Accordingly, in both chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs, the expression of type II collagen was increased significantly in HBP-A group when compared with control group (P<0.001).

CONCLUSIONSThe study documented that the potential pharmacological target of glucan HBP-A in chondrocytes monolayer culture and tissue engineered cartilage in vivo may be concerned with the inhibition of catabolic enzymes MMP-3, ADAMTs-5, and increasing of type II collagen expression.

ADAM Proteins ; genetics ; metabolism ; Aggrecans ; genetics ; metabolism ; Alginates ; pharmacology ; Animals ; Cartilage, Articular ; drug effects ; physiology ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; Cell Survival ; drug effects ; Chondrocytes ; cytology ; drug effects ; metabolism ; ultrastructure ; Collagen Type II ; genetics ; metabolism ; Female ; Glucans ; pharmacology ; Glucuronic Acid ; pharmacology ; Hexuronic Acids ; pharmacology ; Hydrogel, Polyethylene Glycol Dimethacrylate ; pharmacology ; Immunohistochemistry ; Matrix Metalloproteinase 3 ; metabolism ; Mice, Nude ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Tissue Engineering ; methods

BACKGROUNDOlfactory ensheathing cell (OEC) transplantation is a promising or potential therapy for spinal cord injury (SCI). However, the effects of injecting OECs directly into SCI site have been limited and unsatisfied due to the complexity of SCI. To improve the outcome, proper biomaterials are thought to be helpful since these materials would allow the cells to grow three-dimensionally and guide cell migration.

METHODSIn this study, we made a new peptide hydrogel scaffold named GRGDSPmx by mixing the pure RADA16 and designer peptide RADA16-GRGDSP solution, and we examined the molecular integration of the mixed nanofiber scaffolds using atomic force microscopy. In addition, we have studied the behavior of OECs in GRGDSPmx condition as well as on RADA16 scaffold by analyzing their phenotypes including cell proliferation, apoptosis, survival, and morphology.

RESULTSThe experimental results showed that GRGDSPmx could be self-assembled to form a hydrogel. Inverted optical microscopic and scanning electron microscopic analyses showed that OECs are viable and they proliferate within the nanostructured environment of the scaffold. Thiazolyl blue (MTT) assay demonstrated that OEC proliferation rate was increased on GRGDSPmx scaffold compared with the pure RADA16 scaffold. In addition, OECs on GRGDSPmx scaffolds also showed less apoptosis and maintained the original spindle-shaped morphology. Calcein-AM/PI fluorescence staining revealed that OECs cultured on GRGDSPmx grew well and the viable cell count was 95%.

CONCLUSIONThese results suggested that this new hydrogel scaffold provided an ideal substrate for OEC three-dimensional culture and suggested its further application for SCI repair.

Animals ; Cell Proliferation ; Cells, Cultured ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Immunohistochemistry ; Male ; Microscopy, Atomic Force ; Microscopy, Confocal ; Olfactory Bulb ; cytology ; Peptides ; chemistry ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

Starting from the form of red blood cells and the hematocrit (Hct, about 45 vol% of whole blood), we tried to prepare a kind of microspheres suspension to imitate non-Newtonian fluid property of whole blood, exploring its potentiality to be applied in blood viscosity quality control substance. In our study, we produced Ca-alginate hydrogel microspheres using emulsion polymerization, then we suspended the microspheres in 0.9 wt% NaCl solution to obtain a kind of liquid sample with the microspheres taking 45% volume. Then we used two types of viscometers to measure and analyse the changes of sample viscosity at different shear rate. We observed the forms of Ca-alginate hydrogel microspheres with microscope, and found them to be relatively complete, and their diameters to be normally distributed. Diameters of about 90% of the microspheres were distributed in a range from 6 to 22 micron. The samples were examined with viscometer FASCO-3010 and LG-R-80c respectively, both of which have shown a shear-thinning effect. After 5-week stability test, the CV of viscosity results corresponding to the two instruments were 7.3% to 13.8% and 8.9% to 14.2%, respectively. Although some differences existed among the results under the same shear rate, the general variation trends of the corresponding results were consistent, so the sample had the potentiality to be widely used in calibrating a different type of blood viscometer.
Alginates ; chemistry ; Blood Viscosity ; Calcium ; chemistry ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Microspheres ; Plasma Substitutes ; chemistry ; Rheology ; instrumentation ; Suspensions ; chemistry

The present research was aimed to explore the biocompatibility of IKVAV self-assembling peptide nanofiber scaffold with olfactory ensheathing cells (OECs) of rats. The OECs were seeded onto the surface of coverslips covered with IKVAV self-assembling peptide nanofiber scaffold hydrogel (2D culture system), and implanted within IKVAV self-assembling peptide nanofiber scaffold hydrogel (3D culture system), respectively. The adhesion, viability of OECs were observed with inverted microscope. Then the characteristics for survival and adhesion of cells by image processing were observed, and statistical analysis on the number of S-100 positive cell, the area of the cell bodies and the perimeter of the cell and MTT method were carried out. It was found that the OECs could survive and migrate in IKVAV self-assembling peptide nanofiber scaffold. The result of the cell MTT exam, of the shape and quantity of cells had no significant difference compared to those of the OECs cultured with poly-L-lysine (PLL). It has been proved that IKVAV self-assembling peptide nanofiber scaffold has good biocompatibility with rat OECs.
Animals ; Animals, Newborn ; Biocompatible Materials ; chemistry ; Cell Proliferation ; Cells, Cultured ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Laminin ; chemistry ; Nanofibers ; chemistry ; Olfactory Bulb ; cytology ; drug effects ; Peptide Fragments ; chemistry ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

Articular osteocartilage injury caused by trauma or bone disease is very common in clinical practices,the proportion of cartilage defects reached 40.31%. As the low self healing abilities of articular cartilage, the technology of tissue engineering becomes a new method to treat articular cartilage injuries with regenerative medicine. Scaffolds can be divided into preformed and hydrogel scaffolds according to properties. The traditional graft of pre-formed scaffold will bring the secondary injury to the cartilage around the defect, and the loose graft intergration with the defect surface is still a problem. Repairing irregular articular cartilage defects with ideal biomimic materials on the basis of avoiding secondary damage will become a main issue. The method of minimally invasive injecting, biomimics, and in situ remodeling brings hope to articular cartilage repairing. Below is a summary of the international and domestics reference data of recent years on collagen hydrogel in cartilage tissue engineering.
Collagen ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; Tissue Engineering ; methods

BACKGROUNDCapsular contracture has become the most common complication associated with breast implant. Transforming growth factor-beta (TGF-β) is well known for a prominent role in fibrotic diseases. Due to the critical role of TGF-β in pathogenesis of capsular formation, we utilized thermosensitive C/GP hydrogel to controlled release of TGF-β receptor kinase inhibitor (SD208) and investigated their effects on capsular contracture.

METHODSIn vitro degradation and drug release of C/GP hydrogel were performed. Twenty-four rabbits underwent subpanniculus implantation with 30 ml smooth silicone implants and were randomly divided into four groups as follows: Group 1 received saline solution; Group 2 received SD208; Group 3 received SD208-C/GP; Group 4 received C/GP. At 8 weeks, the samples of capsular tissues were analyzed by hematoxylin and eosin and immunohistological staining. The mRNA expression of collagen III and TGF-β1 was detected by RT-PCR assay.

RESULTSC/GP hydrogel could be applied as an ideal drug delivery vehicle which supported the controlled release of SD208. SD208-C/GP treatment showed a significant reduction in capsule thickness with fewer vessels. The histological findings confirmed that the lower amounts of inflammatory cells and fibroblasts infiltrate in SD208-C/GP group. In contrast, typical capsules with more vessel predominance were developed in control group. We did not observe the same inhibitory effect of SD208 or C/GP treatment on capsular contracture. Moreover, SD208-C/GP therapy yielded an evident down-regulation of collagen III and TGF-β1 mRNA expression.

CONCLUSIONSThis study demonstrated that controlled release of TGF-β receptor kinase inhibitor from thermosensitive C/GP hydrogel could significantly prevent capsule formation after mammary implants.

Animals ; Breast Implantation ; adverse effects ; Chitosan ; chemistry ; Glycerophosphates ; chemistry ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Immunohistochemistry ; Protein Kinase Inhibitors ; administration & dosage ; therapeutic use ; Rabbits ; Receptors, Transforming Growth Factor beta ; antagonists & inhibitors ; Reverse Transcriptase Polymerase Chain Reaction

The amphiphilic polypeptide (PA) was self-assembled into three-dimensional (3-D) porous complex of hydrogel and cells with the addition of NSCs-containing DMEM/F12. Cell differentiation in the surface and that within hydrogel were described. Cells harvested from the cerebral cortex of neonatal mice were triturated and cultivated in serum-free media. 1wt% PA was added into same volume of DMEM/F12 with cell concentration of 1 x 10(5)/ml and self-supported into 3-D hydrogel-cell composition; cells suspended within hydrogel being maintained (Experiment group, EG). lwt% PA was self-assembled into two-dimensional (2-D) hydrogel films triggered by addition of DMEM/F12, and then 1 x 10(5)/ml NSCs was seeded in the surface of films (Control group, CG). Cells in EG and CG were incubated in serum-free media for two weeks and stained with immunocytochemistry methods. TEM showed that the hydrogel derived from PA was composed of network nanofibers with their diameter ranging from 3 to 5 nm and length ranging from 100 nm to 1. 5 microm. Above 50% of cells obtained were Nestin positive cells. LSCM observations demonstrated that above 90% of cells survived two days after incubation within hydrogel, and were differentiated into NF and GFAP positive cells one week after incubation, their differentiation rates were 50% +/- 4.2% and 20% +/- 2.8% respectively; however, cells in CG were also differentiated into NF and GFAP positive cells, their differentiation rates were only 40% +/- 3.4% and 31% +/- 2.3% separately. Peptide-based hydrogel was able to provide 3-D environments for cell survival and induce primarily the differentiation of NSCs into neurons. Our data indicated that peptide-directed self-assembly of hydrogels was useful and it served as the neotype nerve tissue engineering scaffolds.
Animals ; Animals, Newborn ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Cells, Cultured ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; metabolism ; Nanofibers ; chemistry ; Neural Stem Cells ; cytology ; Neurogenesis ; drug effects ; Peptides ; chemistry ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tissue Scaffolds ; chemistry

In view of the problems that conventional artificial cartilages have no bioactivity and are prone to peel off in repeated uses as a result of insufficient strength to bond with subchondral bone, we have designed and prepared a novel kind of PVA-BG composite hydrogel as bionic artificial articular cartilage/bone composite implants. The effects of processes and conditions of preparation on the mechanical properties of implant were explored. In addition, the relationships between compression strain rate, BG content, PVA hydrogels thickness and compressive tangent modulus were also explicated. We also analyzed the effects of cancellous bone aperture, BG and PVA content on the shear strength of bonding interface of artificial articular cartilage with cancellous bone. Meanwhile, the bonding interface of artificial articular cartilage and cancellous bone was characterized by scanning electron microscopy. It was revealed that the compressive modulus of composite implants was correspondingly increased with the adding of BG content and the augments of PVA hydrogel thickness. The compressive modulus and bonding interface were both related to the apertures of cancellous bone. The compressive modulus of composite implants was 1.6-2.23 MPa and the shear strength of bonding interface was 0.63-1.21 MPa. These results demonstrated that the connection between artificial articular cartilage and cancellous bone was adequately firm.
Biocompatible Materials ; chemistry ; Biomimetic Materials ; chemistry ; Bone Substitutes ; chemical synthesis ; chemistry ; Cartilage, Articular ; physiology ; surgery ; Compressive Strength ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Polyvinyl Alcohol ; chemistry ; Prostheses and Implants ; Prosthesis Design ; Stress, Mechanical