Design of hemocompatible poly(DMAEMA‐co‐PEGMA) hydrogels for controlled release of insulin

This works aims at (i) studying the antiadhesive properties and the hemocompatibility of poly[2‐(dimethylamino)ethyl methacrylate]‐co‐poly[(ethylene glycol)methacrylate] [poly(DMAEMA‐co‐PEGMA)] copolymers and (ii) investigating the insulin delivery kinetics through hydrogels at physiological pH. A series of poly(DMAEMA‐co‐PEGMA) hydrogels have been synthesized, and their controlled composition was confirmed by X‐ray photoelectron spectroscopy. Then, antibiofouling properties of hydrogels—fibrinogen, erythrocytes, and thrombocytes adhesion—are correlated to their molecular compositions through their hydrophilic properties. As DMAEMA/PEGMA ratio of 70/30 (D70) offers the best compromise between pH sensitivity and hemocompatibility, it is selected for investigating the kinetic rate of insulin release at physiological pH, and the diffusion coefficient of insulin in gel is found to be 0.64 × 10^?7 cm² s^?1. Overall, this study unveils that poly(DMAEMA‐co‐PEGMA) copolymers are promising hemocompatible materials for drug delivery systems. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42365.     

Formulation of silver chloride/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (AgCl/PHBV) films for potential use in bone tissue engineering

Orthopedic implant failure due to bacterial infection has been a concern in bone tissue engineering. Here, we have formulated a composite made of biodegradable polymer, i.e., poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), and silver chloride. Ag⁺ ions released from the AgCl/PHBV film can promote an aseptic environment by promoting inhibition of bacterial growth while maintaining bone cell growth, depending on AgCl loading. The objective of this study is to formulate AgCl/PHBV film(s) of varying composition so as to evaluate the dependence of AgCl loading in the film on antimicrobial activity and cytotoxicity. The release kinetics of silver ions from AgCl/PHBV film in aqueous and Dulbecco's Modified Eagle Medium showed similarity in the initial burst of ions during the first day of desorption followed by a gradual release of ions over extended time period. The antibacterial efficacy of AgCl/PHBV film against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa was evaluated by microbiological assay, while cytotoxicity of the film toward MC3T3‐E1 cells was determined by MTT assay. For all compositions studied, a clear zone of inhibition around AgCl/PHBV film was noticed on a modified Kirby‐Bauer disk diffusion assay. We established that MC3T3‐E1 cell attachment on AgCl/PHBV film is strongly related to loading of AgCl in the film. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45162.     

Incorporation of chloramphenicol and captopril into poly(GL)‐b‐poly(GL‐co‐TMC‐co‐CL)‐b‐poly(GL) monofilar surgical sutures

Incorporation of chloramphenicol and captopril into coated and uncoated monofilament sutures was evaluated, as well as the derived bactericide and wound healing effects. To this end, a commercially available suture and an amorphous random copolymer constituted by trimethylene carbonate and lactide units were considered. The suture had a segmented architecture based on polyglycolide hard blocks and a soft block constituted by glycolide, trimethylene carbonate and ε‐caprolactone units. Chloramphenicol was better loaded when the coating copolymer was employed due to its protective effect whereas captopril showed an opposite behavior due to partial solubilization during immersion in the coating bath. Interestingly, the release behavior was very different for the two studied drugs since a significant retention of chloramphenicol was always detected, suggesting the establishment of interactions between drug and copolymers. On the other hand, delivery of captopril showed a typical dose dependent behavior. A low in vitro toxicity of the two drugs was determined considering both epithelial‐like and fibroblast‐like cells. Bactericide effect of chloramphenicol against Gram‐negative and Gram‐positive bacteria was demonstrated at a dose that was non‐toxic for all assayed cells. An accelerating wound healing effect of captopril was also demonstrated for early events. In this case, the use of a coating copolymer was fundamental to avoid cytotoxic effects on highly loaded sutures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44762.     

Silver nanoparticle incorporated poly(l‐lactide‐co‐glycolide) nanofibers: Evaluation of their biocompatibility and antibacterial properties

The objective of this work is the fabrication of poly(l ‐lactide‐co‐glycolide) or PLGA (with LA/GA ratios of 50/50 and 75/25) nanofibers containing silver nanoparticles (AgNPs) by the method of electrospinning. The incorporation of AgNPs in PLGA was carried out in three different concentrations (1, 3, 6 w/w %).The electrospun nanofibers were evaluated for their morphology by scanning electron microscopy and their fiber diameters ranged between 487 and 781 nm. Integration of AgNPs within the fibers was verified by spectroscopy studies, while the mechanical properties of the developed fibers were found comparable to the mechanical properties of the human skin. Proliferation of human dermal fibroblasts (HDF) demonstrated minimal cytotoxicity on fibers containing 1 wt % and 3 wt % of AgNPs, while 6 wt % of AgNPs inhibited cell proliferation. Antimicrobial activity was studied using three different strains of Gram‐positive and Gram‐negative bacteria. Results of the HDF proliferation and antimicrobial studies showed that the electrospun PLGA75/25 containing 3 wt % AgNP can function as a suitable substrate for wound dressing, compared to the other scaffolds of this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42686.     

Oligonucleotides‐decorated‐poly(N‐vinyl pyrrolidone) nanogels for gene delivery

Pulsed electron‐beam irradiation of a semi‐dilute poly(N‐vinyl pyrrolidone) (PVP) aqueous solution in the presence of acrylic acid has led to a carboxyl functionalized nanogel system. Nanoparticles hydrodynamic size and surface charge density, in water and as a function of pH, were investigated by dynamic light scattering and laser doppler velocimetry, respectively. Nanogels (NGs) were proved not to be cytotoxic at the cellular level. Indeed, they rapidly bypass the cellular membrane to accumulate in specific cell portions of the cytoplasm, in the perinuclear area. The availability of pendant carboxyl groups on the crosslinked PVP NGs core prompted us to attempt their decoration with a single strand oligonucleotide, which holds a terminal amino group. The recognition ability of the attached single helix of its complementary strand was investigated. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39774.     

Release of dexamethasone from poly(N‐vinyl pyrrolidone‐co‐n‐hexyl methacrylate) copolymers of controlled hydrophilicity

A copolymer system with controlled hydrophilicity has been prepared through copolymerization technique and its capability as controlled drug release carrier is investigated. The effect of copolymer composition on water uptake, thermal properties, and morphology is reported. The water uptake increases with increasing N‐vinyl pyrrolidone content and diffusion of water molecules appears to be non‐Fickian. Dexamethasone has been selected as model drug and its controlled release from selected water stable copolymers follows for more than 1 month. Initial burst release of more than 50% occurs in 7 days. The remaining drug is released in a sustained way upto 37 days. Initial 10 h drug release pattern involves first‐order kinetics (NH73) and zero‐order kinetics (NH55), whereas initial 60% drug release mechanism appears to be non‐Fickian for NH73 (n = 0.71) and Case II transport (n = 1.24) for NH55. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Compressive properties and creep resistance of a novel,porous, semidegradable poly(vinyl alcohol)/poly(lactic‐co‐glycolic acid) scaffold for articular cartilage repair

Tissue engineering for articular cartilage repair has shown success in ensuring the integration of neocartilage with surrounding natural tissue, but the rapid restoration of biomechanical functions remains a significant challenge. The poly(vinyl alcohol) (PVA) hydrogel is regarded as a potential articular cartilage replacement for its fair mechanical strength, whereas its lack of bioactivity limits its utility. To obtain a scaffold possessing expected bioactivity and initial mechanical properties, we herein report a novel salt‐leaching technique to fabricate a porous PVA hydrogel simultaneously embedded with poly(lactic‐co‐glycolic acid) (PLGA) microspheres. Through the investigation of environmental scanning electron microscopy, we found that the porous PVA/PLGA scaffold was successfully manufactured. The compression and creep properties were also comprehensively studied before and after cell culturing. The relationship between the compressive modulus and strain ratio of the porous PVA/PLGA scaffold showed significant nonlinear behavior. The elastic compressive modulus was influenced a little by the porogen content, whereas it went higher with a higher PLGA microsphere content. The cell‐cultured scaffolds presented higher compressive moduli than the initial ones. The creep resistance of the cell‐cultured scaffolds was much better than that of the initial ones. In all, this new scaffold is a promising material for articular cartilage repair. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40311.     

Preparation and characterizations of superparamagnetic iron oxide‐embedded poly(2‐hydroxyethyl methacrylate) nanocarriers

The present study aims at formulating a novel multifunctional biocompatible superparamagnetic nanoparticles carrier system with homogeneously dispersed magnetic material in solid polymer matrix of poly(2‐hydroxyethyl methacrylate) (PHEMA). The nanocomposites were designed by modified suspension polymerization of 2‐hydroxyethyl methacrylate followed by in situ coprecipitation of iron oxide inside the nanoparticle matrix yielding magnetic PHEMA (mPHEMA) nanocomposites. The so prepared nanocomposites were characterized by Fourier transform Infrared spectroscopy, X‐ray diffraction technique, Raman spectroscopy, electron diffraction, and energy‐dispersive X‐ray spectroscopy confirming the presence of Fe₃O₄ inside the PHEMA nanoparticles. The magnetization studies of nanocomposites conducted at room temperature using vibrating sample magnetometer suggested for their superparamagnetic nature having saturation magnetization (Ms) of 20 emu/g at applied magnetic field of 5 kOe. Transmission electron microscopy, field‐emission scanning electron microscopy, and dynamic light scattering/zeta potential measurements were also performed which revealed that size of mPHEMA nanocomposites was lying in the range of 60–300 nm having zeta potential of ?93 mV. The nanocomposites showed no toxicity as revealed by cytotoxicity test performed on L‐929 fibroblast by extract method. The results indicated that the prepared superparamagnetic mPHEMA nanocomposites have enormous potential to provide a possible option for magnetically assisted targeted delivery of anticancer drugs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40791.     

Production and characterization of films containing poly(hydroxybutyrate) (PHB) blended with esterified alginate (ALG‐e) and poly(ethylene glycol) (PEG)

Alternative materials have long been studied and developed to replace conventional skin dressings with the emergence of new biopolymers and development of polymeric film fabrication techniques. As a new material for polymeric dressings, films of poly(hydroxybutyrate) (PHB) blended with esterified alginate (ALG‐e) and poly(ethyleneglycol) was studied. The esterification of sodium alginate (ALG‐e) generated a material with some amphiphilic characteristics and increased compatibility with the PHB. PEG was added as plasticizer in PHB/ALG‐e films was also tested, since PEG is often used in blends with PHB to improve flexibility and reduce hydrophobicity. At the amounts studied, it was found that both PEG and ALG‐e increase the degree of crystallinity, but a decrease was observed in the hydrophobic nature of PHB films. At the maximum concentration of ALG‐e and PEG used an increase in water vapor permeability and a decrease in tensile strength was reached due to the synergistic effect caused by better homogenization of PEG and ALG‐e in the PHB matrix. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44362.     

Preparation and evaluation of radioiodinated thermoresponsive polymer based on poly(N‐isopropyl acrylamide) for radiotherapy

A thermoresponsive polymer based on poly N‐isopropylacrylamide (PNIPAM) was synthesized and radioiodinated to explore its potential use in localized radiotherapy. The synthesized PNIPAM polymer was functionalized with L ‐tyrosinamide to facilitate radioiodination. The content of tyrosinamide groups in the polymer was assayed spectrophotometrically (λ = 275nm). The functionalized polymer showed a cloud point temperature of 29–31°C and phase separation at 35°C, as revealed by Differential Scanning Calorimetry (DSC) and Dynamic Light Scattering (DLS). The phase transition temperature is conducive for preferential localization of the polymer at the site of injection due to changes in the polymer conformation at body temperature. For in vivo demonstration, the biodistribution studies of radioiodinated polymer were carried out in Swiss mice bearing fibrosarcoma tumor. Biodistribution studies showed a retention of 30% of the injected labeled polymer, PNIPAM‐¹²⁵I‐tyrosinamide, in the solid tumor tissues after 2 h of intratumoral injection. Although the activity decreased with time, 3–4% of the injected dose (i.d) was found to be retained in the tumor on 5 d post injection. The results suggest the potential use of thermosensitive polymer based on poly N‐isopropylacrylamide for locoregional radionuclide therapy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 860‐868, 2013     

Thermosensitive polymeric micelles based on the triblock copolymer poly(d,l‐lactide)‐b‐poly(N‐isopropyl acrylamide)‐b‐poly(d,l‐lactide) for controllable drug delivery

A thermosensitive amphiphilic triblock copolymer, poly(d,l ‐lactide) (PLA)‐b‐poly(N‐isopropyl acrylamide) (PNIPAAM)‐b‐PLA, was synthesized by the ring‐opening polymerization of d,l ‐lactide; the reaction was initiated from a dihydroxy‐terminated poly(N‐isopropyl acrylamide) homopolymer (HO‐PNIPAAM‐OH) created by radical polymerization. The molecular structure, thermosensitive characteristics, and micellization behavior of the obtained triblock copolymer were characterized with Fourier transform infrared spectroscopy, ¹H‐NMR, gel permeation chromatography, dynamic light scattering, and transmission electron microscopy. The obtained results indicate that the composition of PLA‐b‐PNIPAAM‐b‐PLA was in good agreement with what was preconceived. This copolymer could self‐assemble into spherical core–shell micelles (ca. 75–80 nm) in aqueous solution and exhibited a phase‐transition temperature around 26 °C. Furthermore, the drug‐delivery properties of the PLA‐b‐PNIPAAM‐b‐PLA micelles were investigated. The drug‐release test indicated that the synthesized PLA‐b‐PNIPAAM‐b‐PLA micelles could be used as nanocarriers of the anticancer drug adriamycin (ADR) to effectively control the release of the drug. The drug‐delivery properties of PLA‐b‐PNIPAAM‐b‐PLA showed obvious thermosensitive characteristics, and the release time of ADR could be extended to 50 h. This represents a significant improvement from previous PNIPAAM‐based drug‐delivery systems. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45304.     

Controlled DNA interpolyelectrolyte complex formation or dissociation via stimuli‐responsive poly(vinylamine‐co‐N‐vinylisobutylamide)

Poly(vinylamine‐co‐N‐vinylisobutylamide) or poly(VAm‐co‐NVIBA) was evaluated for its ability to stabilize double‐stranded DNA (dsDNA) with the controlled formation or dissociation of polyion complexes. The poly(VAm‐co‐NVIBA) copolymer consists of the cationic poly(vinylamine) (VAm) that electrostatically binds to the anionic DNA and the thermally responsive poly(N‐isobutylamide) (NVIBA) that helps limit the strength of the electrostatic interaction and prevents the alteration of the DNA helical structure. Agarose gel electrophoresis showed the successful complexation between dsDNA and poly(VAm‐co‐NVIBA). Moreover, DNA was released from the complex at 65 °C, but not at 25 °C. Thus, the NVIBA component in the copolymer played an important role in controlling the process of complex formation or dissociation according to the pH and temperature. The results showed that the molecular design of polycations with a thermoresponsive part is a potential strategy to allow the controllable formation and dissociation of the copolymer/dsDNA complex while avoiding changes to the DNA helical structure. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43852.     

Effects of copolymer microstructure on the properties of electrospun poly(l‐lactide‐co‐ε‐caprolactone) absorbable nerve guide tubes

The main objective of this work has been to study the effects of copolymer microstructure, both chemical and physical, on the microporosity, in vitro hydrolytic degradability and biocompatibility of electrospun poly(l ‐lactide‐co‐ε‐caprolactone), PLC, copolymer tubes for potential use as absorbable nerve guides. PLC copolymers with L : C compositions of 50 : 50 and 67 : 33 mol % were synthesized via the ring‐opening copolymerization of l ‐lactide (L) and ε‐caprolactone (C) at 120°C for 72 h using stannous octoate (tin(II) 2‐ethylhexanoate) and n‐hexanol as the initiating system. Electrospinning was carried out from solution in a dichloromethane/dimethylformamide (7 : 3 v/v) mixed solvent at room temperature. The in vitro hydrolytic degradation of the electrospun PLC tubes was studied in phosphate buffer saline over a period of 36 weeks. The microporous tubes were found to be gradually degradable by a simple hydrolysis mechanism leading to random chain scission. At the end of the degradation period, the % weight retentions of the PLC 50 : 50 and 67 : 33 tubes were 15.6% and 70.2%, respectively. Pore stability during storage as well as cell attachment and proliferation of mouse fibroblast cells (L929) showed the greater potential of the PLC 67 : 33 tubes for use as temporary scaffolds in reconstructive nerve surgery. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4357–4366, 2013     

Synthesis and characterization of a novel stimuli‐responsive magnetite nanohydrogel based on poly(ethylene glycol) and poly(N‐isopropylacrylamide) as drug carrier

A novel stimuli‐responsive magnetite nanohydrogel (MNHG), namely [poly(ethylene glycol)‐block‐poly(N‐isopropylacrylamide‐co‐maleic anhydride)₂]‐graft‐poly(ethylene glycol)/Fe₃O₄ [PEG‐b‐(PNIPAAm‐co‐PMA)₂]‐g‐PEG/Fe₃O₄, was successfully developed. For this purpose, NIPAAm and MA monomers were block copolymerized onto PEG‐based macroinitiator through atom transfer radical polymerization technique to produce PEG‐b‐(PNIPAAm‐co‐PMA)₂. The synthesized Y‐shaped terpolymer was crosslinked through the esterification of maleic anhydride units using PEG chains to afford a hydrogel. Afterward, magnetite nanoparticles were incorporated into the synthesized hydrogel through the physical interactions. The chemical structures of all synthesized samples were characterized using Fourier transform infrared and proton nuclear magnetic resonance spectroscopies. Morphology, thermal stability, size, and magnetic properties of the synthesized MNHG were investigated. In addition, the doxorubicin hydrochloride loading and encapsulation efficiencies as well as stimuli‐responsive drug release ability of the synthesized MNHG were also evaluated. The drug‐loaded MNHG at physiological condition exhibited negligible drug release values. In contrast, at acidic (pH 5.3) condition and a little bit higher temperature (41 °C) the developed MNHG showed higher drug release values, which qualified it for cancer chemotherapy due to especial physiology of cancerous tissue in comparison with the surrounding normal tissue. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46657.     

Poly(l‐histidine)‐containing polymer bioconjugate hybrid materials as stimuli‐responsive theranostic systems

For decades, researchers have aspired to develop materials for noninvasive treatment and monitoring of pathological conditions. Various organs, tissues, subcellular compartments, and their pathophysiological states can be characterized by their pH values. pH‐dependent intracellular tumor targeting has received particular attention due to the unique acidic environment of the solid tumors created by physiological and metabolical abnormalities. Responsive nanocarriers, when exposed to these pH stimuli, respond quickly to the physicochemical changes by undergoing structural deformations, such as swelling and phase transition, which favors the drug release specifically at the diseased site. Recently, researchers have developed several new poly(L ‐histidine) (p(His))‐based pH responsive systems for sustained drug release and molecular targeting. This review focuses on the p(His)‐based pH responsive nanocarriers, which are utilized in biomedical applications such as anti‐cancer drug delivery and nucleic acid delivery. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40796.     

Effects of wide‐range γ‐irradiation doses on the structures and properties of 4,4′‐dicyclohexyl methane diisocyanate based poly(carbonate urethane)s

For medical applications, 4,4′‐dicyclohexyl methane diisocyanate (HMDI)‐based poly(carbonate urethane)s were synthesized from HMDI and 1,4‐butanediol as hard segments and poly(carbonate diol) (number‐average molecular weight = 2000 g/mol) as soft segments. The effects of wide‐range γ irradiation on the samples were examined through a series of analytical techniques. Scanning electron microscopy revealed that γ irradiation etched and roughened the surfaces of the irradiated samples. The gel content and crosslinking density measurements confirmed that crosslinking occurred along with degradation at all of the investigated irradiation doses and the degree of both crosslinking and degradation increased with increasing irradiation dose. Fourier transform infrared spectroscopy demonstrated that chain scission in the γ‐irradiated samples occurred at the carbonate and urethane bonds. The decreasing molecular weight and tensile strength indicated that the degradation increased with the γ‐irradiation dose. Differential scanning calorimetry and dynamic mechanical thermal analysis indicated that γ irradiation had no significant effect on the phase‐separation structures. There was a slight reduction in the contact angle. An evaluation of the cytotoxicity demonstrated the nontoxicity of the nonirradiated and irradiated polyurethanes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41049.     

pH‐sensitive keratin‐based polymer hydrogel and its controllable drug‐release behavior

Using feather keratin as biocompatible and inexpensive natural biopolymer and methacrylic acid as a functional monomer, we prepared a pH‐sensitive feather‐keratin‐based polymer hydrogel (FKPGel) with grafted copolymerization. The obtained FKPGel was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The swelling behavior and pH sensitivity of the FKPGel were investigated. When the small molecule (rhodamine B) and macromolecule (bovine serum albumin) were used as model drug molecules, the FKPGel exhibited controllable release behavior in vitro, and the hydrogels had pH sensitivity. For a small molecular drug, the cumulative release rate was 97% in 24 h at pH 8.4. For macromolecular drug, the cumulative release rate reached 89% at pH 7.4. Its release behavior could be controlled by the pH value. In summary, a simple method was found to reuse disused feathers. It is a kind of pH‐sensitive hydrogels to be applied in drug‐delivery systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41572.     

Modified poly(caprolactone trifumarate) with embedded gelatin microparticles as a functional scaffold for bone tissue engineering

Bone tissue engineering offers high hopes in reconstructing bone defects that result from trauma, infection, tumors, and other conditions. However, there remains a need for novel scaffold materials that can effectively stimulate ossification with appropriate functional properties. Therefore, a novel injectable, biodegradable, and biocompatible scaffold made by incorporating modified poly(caprolactone trifumarate) (PCLTF) with embedded gelatin microparticles (GMPs) as porogen is developed. Specifically, in vitro and in vivo tests were carried out. For the latter, to determine the osteogenic ability of PCLTF‐GMPs scaffolds, and to characterize bone‐formation, these scaffolds were implanted into critical‐sized defects of New Zealand white rabbit craniums. Field Emission Scanning Electron Microscope (FESEM) demonstrated cells of varying shapes attached to the scaffold surface in vitro. The PCLTF‐GMPs demonstrated improved biocompatibility in vivo. Polyfluorochrome tracers detected bone growth occurring in the PCLTF‐GMPs filled defects. By incorporating PCLTF with GMPs, we have fabricated a promising self‐crosslinkable biocompatible and osteoconducive scaffold for bone tissue engineering. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43711.     

Design and in vivo assessment of polyester copolymers based on trimethylene carbonate and ε‐caprolactone

Poly(trimethylene carbonate‐co‐caprolactone) (PTCL) copolymers with various trimethylene carbonate ratios were synthesized by ring‐opening polymerization and were used to prepare implants for an in vivo experiment. Medical silicone rubber was used as the control. Implants were prepared by compression molding with a laboratory instrument. The properties of these copolymer implants were investigated. PTCL implants and silicone rubbers were implanted subcutaneously in the dorsal region of New Zealand white rabbits. The assessment was performed 1, 2, 3, 4, 5, 6, 7, and 8 months postoperatively by the determination of the weight loss, water uptake, thermal behavior, molecular weight of the explanted implants, and histological examination. During the 8‐month implantation, the value of maximum weight loss was found to be 25%. A continuous decrease in the molecular weight occurred. No remarkable tissue reactions were observed during degradation, and foreign‐body reactions were similar to those of silicone rubbers, which are commercially available materials. In this study, we aimed to indicate the likely clinical behavior but good biodegradable properties of PTCL copolymers compared to those of silicone rubber. This may open a new avenue of application for them in the drug industry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41815.     

Fluorescent poly(hydroxyurethane): Biocompatibility evaluation and selective detection of Fe(III)

Polyurethane (PU) is widely used in biomedical applications owing to its excellent physical and chemical properties. As an isocyanate‐free PU material, fluorescent poly(hydroxyurethane) (FPHU) is synthesized from the addition of the cyclic carbonates with amines rather than the toxic isocyanate with diols, which reduces the possible injury to the human due to trace amounts of the isocyanate residues. Herein, we report the biocompatibility of a FPHU that can be synthesized from carbon dioxide, bisepoxides, and diamine in tandem. Of unique, FPHU exhibits a strong blue fluorescence and is selectively sensitive to Fe³⁺ with a detection limit of 4.56 μM. The overall results of the methylthiazolyldiphenyl‐tetrazolium, cytokine release, and hemolysis assays for FPHU indicates that FPHU has much lower cytotoxicity and immunotoxicity compared with the traditional isocyanate PU, as well as a good blood compatibility with less than 5% hemolysis rate. Therefore, FPHU presents as a kind of safer PU and can be prospectively applied in medical materials.