The properties of biomedical intelligent polymer materials can be changed obviously when there is a little physical or chemical change in external condition. They are in the forms of solids, solutions and polymers on the surface of carrier, including aqueous solution of hydrophilic polymers, cross-linking hydrophilic polymers (i.e. hydrogels) and the polymers on the surface of carrier. In this paper are reviewed the progress in researches and the application of biomedical intelligent polymer materials.
Biocompatible Materials ; chemistry ; Biotechnology ; Chemical Phenomena ; Chemistry, Physical ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Polymers ; chemistry ; Surface Properties

In this study, using ethylene carbonate and ethanolamine, we synthesized a novel diol chain-extender, bis-hydroxylethyl carbomate (EC-AE), which contains carbomate structure. The polyurethanes, PUA25 and PUB25, with different extenders, EC-AE and BDO, were synthesized by one-step polymerization, respectively. Their structures were characterized by using FT-IR and DSC. The results indicated that the microphase separation degree of PUA25 was less than that of PUB25, in other words, the amount of hydrogen bonding between hard segments and soft segments in PUA25 was superior to that in PUB25. And the formation of physically crosslinked hydrogels prepared by PUA25 and PUB25 were studied in detail. It was found that only PUA25 can form hydrogel in situ from solution state by cooling. And this kind of hydrogels showed the transition cycle of "gel-sol-gel" under "cooling-heating-cooling" thermal cycles, respectively. The results suggested that the physically crosslinked polyurethane hydrogels were easily possessed in high degree of phase mixing.
Biocompatible Materials ; Cross-Linking Reagents ; chemistry ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemical synthesis ; chemistry ; Polyurethanes ; chemical synthesis ; chemistry

The neotype of amphiphilic oligopeptide (C16 H31 O-AAAGGGGDDIKVAV) was synthesized. The framework of three-dimensional and porous hydrogel self-assembly from the amphiphilic oligopeptide on different conditions was explored. The peptide, whose molecular weight (MW) and purity were detected by Mass Spectrometer (MS) and High Performance Liquid Chromatograph (HPLC) respectively, was synthesized in solid phase methods. Peptide was dissolved in 0.1 mol/L Sodium Hydroxide (NaOH) solution. 200 microl of 10, 2, 1, 0.5 wt% peptide solutions, which were prepared respectively, were added into the same volume of DMEM/F12, or placed into the vapor of 10 mol/L Hydrochloric acid (HCl), or were used to coat in the surface of coverslip and set into the baking oven at 37 degrees C. The self-assembly hydrogel was examined with transmission electron microscope (TEM) and scanning electron microscope (SEM). MS showed that peptide MW was 1438.31. HPLC testified that the peptide purity was 96%. The peptide solution was self-supported into hydrogel triggered with DMEM/F12 in few seconds, or the thin hydrogel after two hours in the vapor of 10 mol/L HCl, or not hydrogel in the baking oven at 37 degrees C. SEM showed that the hydrogel self-assembly from 10 wt% peptide solution was composed of nanofibers that ranked in layers where there were thick voids. TEM showed that the hydrogel self-assembly from 2, 1, 0.5 wt% peptide solution comprised woven network nanofibers, that the nanofibers of hydrogel self-supported from 1 wt% peptide solution varied from 3 to 6 nm in diameter and 100 nm to 1.5 um in length, that the nanofibers of hydrogel self-supported from 2 wt% peptide solution ranked closely, and there were big voids within the thin nanofibers of hydrogel self-supported from 0.5 wt% peptide solution. The amphiphilic oligopeptide was synthesized and self-organized successfully into porous hydrogel characterized as "intelligent" tissue engineering scaffolds containing the bioactive ligand, which was triggered by DMEM/F12.
Biocompatible Materials ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemical synthesis ; chemistry ; Peptides ; chemical synthesis ; chemistry ; Porosity ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

Poly (hydroxyethyl methacrylate) (PHEMA) hydrogel for intraocular lens (IOL) materials was synthesized by solution polymerization using 2-hydroxyethyl methacrylate (HEMA) as raw material, ammonium persulfate and sodium pyrosulfite (KPS/SMBS) as catalyst, and trietyleneglycole dimethacrylate (TEGDMA) as cross-linking additive. Effects of reaction time, temperature, dosage of catalyst and cross-linking additive on mechanical strength and the equilibrium water content (EWC) of the PHEMA hydrogel were systematically investigated and their structure and optical property were also characterized. The experimental results showed that the optimum conditions for preparing PHEMA hydrogel are: catalyst 0.5 wt%, cross-linking additive 1.0 wt%, reaction temperature 40 degrees C, reaction time 36 h. Under the optimum conditions, the tensile strength of PHEMA hydrogel prepared is as high as 0.57 MPa, hardness of Shore A is 23.0, EWC is over 40%, and light transmittance is over 97%.
Biocompatible Materials ; chemistry ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Lenses, Intraocular ; Polyhydroxyethyl Methacrylate ; chemical synthesis ; chemistry ; Tensile Strength

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

BACKGROUND: The tissue engineering and regenerative medicine approach require biomaterials which are biocompatible, easily reproducible in less time, biodegradable and should be able to generate complex three-dimensional (3D) structures to mimic the native tissue structures. Click chemistry offers the much-needed multifunctional hydrogel materials which are interesting biomaterials for the tissue engineering and bioprinting inks applications owing to their excellent ability to form hydrogels with printability instantly and to retain the live cells in their 3D network without losing the mechanical integrity even under swollen state. METHODS: In this review, we present the recent developments of in situ hydrogel in the field of click chemistry reported for the tissue engineering and 3D bioinks applications, by mainly covering the diverse types of click chemistry methods such as Diels–Alder reaction, strain-promoted azide-alkyne cycloaddition reactions, thiol-ene reactions, oxime reactions and other interrelated reactions, excluding enzyme-based reactions. RESULTS: The click chemistry-based hydrogels are formed spontaneously on mixing of reactive compounds and can encapsulate live cells with high viability for a long time. The recent works reported by combining the advantages of click chemistry and 3D bioprinting technology have shown to produce 3D tissue constructs with high resolution using biocompatible hydrogels as bioinks and in situ injectable forms. CONCLUSION: Interestingly, the emergence of click chemistry reactions in bioink synthesis for 3D bioprinting have shown the massive potential of these reaction methods in creating 3D tissue constructs. However, the limitations and challenges involved in the click chemistry reactions should be analyzed and bettered to be applied to tissue engineering and 3D bioinks. The future scope of these materials is promising, including their applications in in situ 3D bioprinting for tissue or organ regeneration.
Biocompatible Materials ; Bioprinting* ; Click Chemistry ; Cycloaddition Reaction ; Hydrogel* ; Hydrogels* ; Ink* ; Regeneration ; Regenerative Medicine ; Tissue Engineering*

BACKGROUND: Early laboratory detection of Mycobacterium tuberculosis is crucial for controlling tuberculosis. We developed a hydrogel mycobacterial culture method that retains the advantages of both solid and liquid methods in terms of speed, cost, and efficiency. METHODS: Mycobacterium bovis bacillus Calmette-Guerin (BCG) suspensions and 200 acid-fast bacilli (AFB)-positive clinical specimens were inoculated in Middlebrook 7H9 liquid media (Becton-Dickinson and Company, USA) and mixed with 75 microL of 9-fluorenylmethoxycarbonyl (Fmoc)-Phe-Phe-OH hydrogel stock solution in an Eppendorf tube just before culture incubation. The mixtures were cultured at 37degrees C for as long as 14 days to monitor culture status. RESULTS: The number of M. bovis BCG increased with time. For 200 AFB smear-positive specimens, 155 of 158 conventional culture-positive specimens and 4 culture-negative or contaminated specimens yielded positive cultures within 14 days. For 128 specimens positive with the liquid culture method, the time to positive culture using the hydrogel method (mean, 12.6 days; range, 7 to 14 days) was significantly shorter than that for conventional liquid culture (mean, 16.2 days; range, 6 to 31 days; P<0.0001). CONCLUSIONS: The hydrogel scaffold culture system is useful for timely, economical, and efficient detection of mycobacteria in clinical specimens.
Bacteriological Techniques/*methods ; Culture Media/chemistry ; Early Diagnosis ; Humans ; Hydrogel/*chemistry ; Mycobacterium tuberculosis/*isolation & purification ; Tuberculosis/diagnosis/*microbiology

Sugar-containing monomer vinylbenzylglycosylallyamide (VBG) was synthesized by vinylbenzyl amine and delta-gluconolactone in dimethylformamide(DMF) solution. The sugar-based hydrogel was prepared by free radical crosslinking copolymerization of VBG, itaconic acid (IA) and acrylamide (AM). The release properties of Aspirin from xerogels matrices and from hydrogel in different pH solutions and different concentration NaCl solutions were studied respectively. The release mechanism of Aspirin was further confirmed by evaluating the n value in Peppas equation. The results indicated that the drug release increased with the increase of pH values and with the decrease of NaCl concentration.
Acrylic Resins ; chemistry ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; chemistry ; Aspirin ; administration & dosage ; chemistry ; Delayed-Action Preparations ; chemical synthesis ; chemistry ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemical synthesis ; chemistry ; Hydrogen-Ion Concentration ; Succinates ; chemistry ; Vinyl Compounds ; chemistry

OBJECTIVETo evaluate the biocompatibility of pectin/poly vinyl alcohol composite (CoPP) hydrogel for use as a prosthetic nucleus pulposus material.

METHODSThe in vitro cytotoxicity of CoPP hydrogel was tested in NCTC L929 cells, which were divided into normal control group, negative control group [treated with poly (vinyl alcohol) hydrogel, PVA], experimental group (treated with CoPP) and positive control group (0.64% phenol). The optical density of the cells on days 2, 4, and 7 of the corresponding treatments was determined and the relative growth rate calculated. For in vivo biocompatibility evaluation, dehydrated CoPP and PVA hydrogel were respectively implanted into the left and right gluteus of SD rats, and the wound healing and general status were observed. The muscular tissues containing the implants were taken 1, 4, and 12 weeks after the implantation for gross observation and microscopic observation of the inflammatory cell infiltration (ICI) and formation of the fibrous capsulation around the implants.

RESULTSThe L929 cells incubated with PVA and CoPP group both grew well, with relative growth rate over 80% and 75%, respectively. The cytotoxicity of PVA and CoPP was both lower than grade 1. In contrast, the relative growth rate in the positive control group was below 24%, with cytotoxicity over grade 4. In the SD rats, ICI of grade IV occurred in the muscular tissues around the PVA and CoPP implants at 1 week without formation of complete capsule, and at 4 weeks, ICI was lowered to grade 1 with grade 4 capsular reaction. Till week 12, the ICI and capsular reaction were both first grade.

CONCLUSIONCoPP hydrogel has in vitro grade 0 or 1 cytotoxicity and causes only mild inflammation after implantation in rats, suggesting good biocompatibility of the material.

Animals ; Biocompatible Materials ; Hydrogel, Polyethylene Glycol Dimethacrylate ; Implants, Experimental ; Intervertebral Disc ; surgery ; Materials Testing ; methods ; Pectins ; chemistry ; Polyvinyl Alcohol ; chemistry ; Rats

Novel hydrogel composed of both chondroitin sulfate (CS) and gelatin was developed for better cellular interaction through two step double crosslinking of N-(3-diethylpropyl)-N-ethylcarbodiimide hydrochloride (EDC) chemistries and then click chemistry. EDC chemistry was proceeded during grafting of amino acid dihydrazide (ADH) to carboxylic groups in CS and gelatin network in separate reactions, thus obtaining CS–ADH and gelatin–ADH, respectively. CS–acrylate and gelatin–TCEP was obtained through a second EDC chemistry of the unreacted free amines of CS–ADH and gelatin–ADH with acrylic acid and tri(carboxyethyl)phosphine (TCEP), respectively. In situ CS–gelatin hydrogel was obtained via click chemistry by simple mixing of aqueous solutions of both CS–acrylate and gelatin–TCEP. ATR-FTIR spectroscopy showed formation of the new chemical bonds between CS and gelatin in CS–gelatin hydrogel network. SEM demonstrated microporous structure of the hydrogel. Within serial precursor concentrations of the CS–gelatin hydrogels studied, they showed trends of the reaction rates of gelation, where the higher concentration, the quicker the gelation occurred. In vitro studies, including assessment of cell viability (live and dead assay), cytotoxicity, biocompatibility via direct contacts of the hydrogels with cells, as well as measurement of inflammatory responses, showed their excellent biocompatibility. Eventually, the test results verified a promising potency for further application of CS–gelatin hydrogel in many biomedical fields, including drug delivery and tissue engineering by mimicking extracellular matrix components of tissues such as collagen and CS in cartilage.
Amines ; Cartilage ; Cell Survival ; Chemistry ; Chondroitin Sulfates ; Chondroitin ; Click Chemistry ; Collagen ; Extracellular Matrix ; Gelatin ; Hydrogel ; Hydrogels ; In Vitro Techniques ; Spectrum Analysis ; Tissue Engineering ; Transplants