Augmentation Mammoplasty With External Volume Expander-Assisted Autologous Fat Grafting in 305 Asian Patients.

BACKGROUND: External volume expander (EVE)-assisted autologous fat grafting is suitable for breast augmentation, but no large sample study in Asia has confirmed this method. OBJECTIVES: The authors reported their experience and outcomes in augmentation mammoplasty with EVE-assisted autologous fat grafting. METHODS: A retrospective study was conducted in 305 female patients who underwent augmentation mammoplasty with EVE-assisted fat grafting between September 2012 and December 2020. Doctors utilized Crisalix (Crisalix S.A., Lausanne, Switzerland) for 3-dimensional (3D) imaging acquisition to measure the increase in breast volume to evaluate doctor satisfaction. The Preoperative Satisfaction with Breast and BREAST-Q questionnaires were employed to assess patients' preoperative and postoperative satisfaction, respectively. RESULTS: The 305 female patients were aged 18 to 50 years (mean, 35.9 years). Among them, 68.52% were "very satisfied," 18.69% were "somewhat satisfied," 11.15% were "somewhat dissatisfied," and 1.64% were "very dissatisfied" based on BREAST-Q analysis, whereas 100% were dissatisfied according to the Preoperative Satisfaction with Breast questionnaire. Doctors employed Crisalix to measure the increase in breast volume to evaluate doctor satisfaction. The results showed 76.01% had an increase in breast volume of 150 to 250 mL or >250 mL and were "satisfied" and "very satisfied," respectively, 21.64% had an increase of 50 to 149 mL and were "somewhat satisfied," and 2.30% had an increase <50 mL and were "dissatisfied." There were no complications, such as obvious fat liquefaction, infection, or fat embolism. CONCLUSIONS: Augmentation mammoplasty with EVE-assisted fat grafting is effective and satisfying in China. Crisalix for 3D imaging acquisition is convenient and effective in measuring breast volume.

Proteinuria can predict short-term prognosis in critically ill cirrhotic patients.

BACKGROUND AND AIM: Increasing evidence supports that proteinuria is a useful tool in several clinical situations. Cirrhotic patients with proteinuria admitted to intensive care units (ICUs) have high mortality rates. This study analyzed the outcomes of critically ill cirrhotic patients and determined the prognostic value of proteinuria. METHODS: A total of 230 cirrhotic patients were admitted to the ICU of a hospital in Taiwan between March 2008 and February 2011. We prospectively collected data, including demographic parameters and clinical characteristics, of patients on day 1 of admission to the ICU and analyzed these variables as predictors of mortality. RESULTS: The overall ICU, hospital, and 90-day mortality rates were 54%, 60%, and 63%, respectively. The patients with proteinuria had higher rates of acute kidney injury (84% vs. 53%, P<0.001), ICU death (60% vs. 25%, P<0.001), and 90-day mortality (79% vs. 40%, P<0.001). Patients with proteinuria had a hazard ratio for 90-day mortality of 2.800 (P<0.001; 95% CI, 1.927-4.069). Multivariate analysis showed that proteinuria and the Sequential Organ Failure Assessment score were predictors of short-term prognosis. CONCLUSIONS: Proteinuria in critically ill cirrhotic patients is associated with increased complications of liver cirrhosis, ICU mortality, and poor short-term prognosis.

A bacteriostatic hemostatic dressing prepared from l-glutamine-modified chitosan, tannic acid-modified gelatin and oxidized dextran.

In this study, porous hemostatic sponges (CGS1, CGS2 and CGS3) with proper absorption (38-43×) and air permeability (2214 g/m2·day) were prepared from l-glutamine-modified chitosan (CG), tannic acid-modified gelatin (GTA), and oxidized dextran (ODEX) by Schiff base crosslinking reaction. Among them, CGS2 was proved to have high porosity (88.98 %), durable water retention (>6 h), strong antibacterial activity, proper mechanical quality, and suitable tissue adhesion. In addition, CGS2 had good biocompatibility, mainly manifested in low hemolysis rate (<0.4 %), low cytotoxicity (relative cell activity>90 %), and good biodegradability in vitro. The hemostatic time and blood loss in CGS2 group were much lower than those in commercial gelatin sponge group in three animal injury models. Moreover, the activated partial thromboplastin time (APTT) and the prothrombin time (PT) results indicated that CGS2 promoted coagulation by activating the endogenous coagulation pathway. These results suggested that CGS2 had great potential for rapid hemostasis and avoidance of wound infection.

Preparation and characterization of antibacterial, antioxidant, and biocompatible p-coumaric acid modified quaternized chitosan nanoparticles.

To fabricate multifunctional nanoparticles (NPs) based on chitosan (CS) derivative, we first prepared quaternized CS (2-hydroxypropyltrimethyl ammonium chloride CS, HTCC) via a one-step approach, then synthesized p-coumaric acid (p-CA) modified HTCC (HTCC-CA) for the first time through amide reaction, and finally fabricated a series of NPs (HTCC-CA NPs) using HTCC-CAs with different substitution degrees and sodium tripolyphosphate (TPP) by ionic gelation. Newly-prepared HTCC and HTCC-CAs were characterized by FT-IR, 1H NMR, elemental analysis (EA), full-wavelength UV scanning, silver nitrate titration, and Folin-Ciocalteu methods. DLS and TEM results demonstrated that three selected HTCC-CA NPs had moderate size (< 350 nm), good dispersion (PDI < 0.4), and positive zeta potential (11-20 mV). The HTCC-CA NPs had high antibacterial activity against six bacterial strains, and the minimum inhibitory concentration (MIC) values were almost the same as the minimum bactericidal concentration (MBC) values (250-1000 µg/mL). Also, the HTCC-CA NPs had good antioxidation (radical scavenging ratio > 65 %) and low cytotoxicity (relative cell viability >80 %) to the tested cells. Totally, HTCC-CA NPs with high antibacterial activity, great antioxidation, and low cytotoxicity might serve as new biomedical materials for promoting skin wound healing.

Breast Augmentation with Autologous Fat Grafting Immediately after Removal of Polyacrylamide Hydrogel and Fibrotic Capsule in 162 Patients.

Objective: In this study, we investigated the feasibility and efficacy of immediate breast augmentation with autologous fat grafting after removal of polyacrylamide hydrogel (PAAG) and fibrotic capsule. Methods: A retrospective study was conducted on 162 female patients who underwent removal of breast filler PAAG and the fibrotic capsule which produced after injection of PAAG via areola omega-shaped incision. Then autologous fat grafting was immediately performed evenly and radially around the areola via the same incision into different layers (subcutaneous, submammary tissue, pectoralis major intramuscular, and inferior pectoralis major space) except the empty cavity. The cavity left by removal of PAAG and fibrous capsule was closed with negative pressure drainage tube and slight external pressure. Results: All patients recovered well without severe complications. The average score of postoperative satisfaction with physical well-being: chest was 99.83 (total score: 100) compared with the average satisfaction score of 71.69 (total score: 100) preoperatively by means of BREAST-Q™ evaluation (p < 0.01). All patients were satisfied with their postoperative breast shape. Conclusions: Removing as much as possible is critical for patients who underwent the PAAG injection. Our experience in immediate breast augmentation with autologous fat grafting after removal of PAAG and fibrotic capsule proved useful and effective to maintain the balance between removing the PAAG as much as possible and retaining soft tissue to reshape breasts. Level of Evidence: IV.

Carboxymethyl chitosan and carboxymethyl cellulose based self-healing hydrogel for accelerating diabetic wound healing.

In this study, a new type of biodegradable, injectable, self-healing, and low-toxic CMCSH, formed by N, O-carboxymethyl chitosan-heparin (CMCS-Hep) and carboxymethyl cellulose-aldehyde (CMC-A), was designed to deliver drug for promoting the progress of the diabetic wound healing. CMCS was modified with Hep for the first time to synthesize CMCS-Hep, and CMC-A was synthesized by the periodate oxidation method. First, SOD encapsulated in the CMCSH was applied to the diabetic wound bed to moderate the microenvironment, then rhEGF retained in the CMCSH was sustainedly released to the wound area. These results indicated that the dual-drug delivery system had the ability to improve drug availability, promote cell migration and proliferation, reduce DNA damage, shorten the inflammatory period, and accelerate the deposition of collagen fibers and the formation of blood vessels in the model with diabetic skin injury, suggesting that CMCSH as drug carriers had positive effects on diabetic wound healing.

Antibacterial porous sponge fabricated with capric acid-grafted chitosan and oxidized dextran as a novel hemostatic dressing.

This work aims to fabricate multifunctional hemostatic sponges (C-ODs). Porous C-ODs were first constructed by using capric acid-modified chitosan (CSCA) and oxidized dextrans (ODs) with different oxidation degrees. Batches of experiments showed that (i) CSCA (33.39% of grafting degree), ODs, and C-ODs (100-200 µm in pore size) were synthesized, evidenced by FT-IR, 1H NMR, elemental analysis, hydroxylamine hydrochloride titration, and SEM results; (ii) among C-ODs, C-OD2 had appropriate porosity (85.0%), swelling (20 times its dry weight), absorption, water retention, water vapor transmission, and mechanical properties; (iii) C-OD2 possessed low toxicity (relative cell viability > 86%), low hemolysis rate (0.65%), suitable tissue adhesion (4.74 kPa), and strong antibacterial efficacy (five strains); and (iv) C-OD2's dynamic blood clotting was within 30 s. In three animal injury models, C-OD2's hemostasis time and blood loss were fairly lower than commercial gelatin sponge. Totally, C-OD2 might serve as an ideal hemostatic dressing.

Novel amidinothiourea-modified chitosan microparticles for selective removal of Hg(II) in solution.

Glutaraldehyde-crosslinked chitosan microparticles (CGP) prepared via the inversed-phase emulsification were successively modified by epichlorohydrin (ECH) and amidinothiourea (AT) as novel adsorbent (CGPET) for selective removal of Hg(II) in solution. FTIR, EA, XPS, SEM-EDX, TG, DTG, and XRD results indicated that CGPET had ample -NH2 and CS, relative rough surface, mean diameter of ~40 µm, great thermal stability, and crystalline degree of 2.4%, beneficial to the uptake of Hg(II). The optimum parameters (pH 5, dosage 1 g/L, contact time 4 h, and initial concentration 150 mg/L) were acquired via batches of adsorption experiments. Adsorption behavior was well described by the Liu isothermal and pseudo-second-order kinetics models, and the maximum adsorption capacity was 322.51 mg/g, surpassing many reported adsorbents. Regeneration and coexisting-ion tests demonstrated that CGPET had outstanding reusability (Rr > 86.89% at the fifth cycle) and selectivity (Rs > 93%). Besides, its potential adsorption sites and mechanisms were proposed.

Chemoradiotherapy for Inoperable Carotid Body Leiomyosarcoma: A Case Report and Review of Literature.

Vascular leiomyosarcoma is an extremely rare tumor and is associated with poor prognosis among leiomyosarcoma. Surgical resection remains the main treatment option. But outcome of definitive treatment with chemoradiotherapy in inoperable patients is not clear. Here, we report treatment and outcome of definitive chemoradiotherapy in a case of vascular leiomyosarcoma. A 64-year-old man with the initial presentation of pulsatile right neck mass was diagnosed with right carotid body leiomyosarcoma. He refused surgical intervention due to risk of carotid body injury and ischemic stroke. Successful tumor control was achieved with carboplatin-based concurrent chemoradiotherapy. Investigational liquid biopsy for circulating sarcoma cells was also performed to analyze drug sensitivity profile of this rare tumor. One year after treatment, the disease remained well controlled and there was no evidence of baroreflex failure or treatment-related late toxicities. To our best knowledge, this is the first case report of right carotid body leiomyosarcoma controlled with definitive concurrent chemoradiotherapy. The approach of personalized multi-modality treatment will be a focus of our future investigation.

Decanoic acid functionalized chitosan: Synthesis, characterization, and evaluation as potential wound dressing material.

Skin wound dressing materials, which can accelerate wound healing and have the synthetic advantages of simplicity, environmental safety, and resource abundance, are becoming a hot topic of research now. Following such a research trend, we prepared novel decanoic acid functionalized chitosan (CSDA) with good solubility by acylation via a facile one-step method. FTIR, 1H NMR, and UV-Vis results demonstrated that alkyl chains were successfully grafted onto C2 positions of chitosan (CS) skeleton through acylation. XRD patterns implied that the crystallinity of CSDA greatly declined due to the introduction of alkyl moieties, favorable for improving water solubility. Conductometric titration results showed that the degrees of substitution of CSDA, CSDA1, and CSDA2 were 41.42, 26.12, and 23.17%, respectively. MTT assay and hemolysis experiments illustrated that all the CSDA samples tested in this work possessed good hemocompatibility (hemolysis rate < 2%) and excellent cytocompatibility (relative cell viability >75%) toward L929 cells. Moreover, CSDA-soaked gauze dressings and full-thickness excisional wound models were employed to estimate the feasibility of CSDA as wound dressing material, and the results displayed that CSDA with the degree of substitution of 41.42% could enhance the wound healing rate to 100% on day 16. Altogether, CSDA might be potential material used as wound dressing.

Fabrication of methyl acrylate and tetraethylenepentamine grafted magnetic chitosan microparticles for capture of Cd(II) from aqueous solutions.

MCS-MA-TEPA microparticles, with 251.22 mg g-1 of adsorption capacity for Cd(II), higher than most of the counterparts, were first fabricated by chemical coprecipitation, spray drying, and Michael addition reaction, without any cross-linker participation. These Fe3O4-nanoparticle-embedded microparticles of 5.95 µm in size, derived from modifications by methyl acrylate (MA) and tetraethylenepentamine (TEPA) on magnetic chitosan (MCS) microparticles, were of plum-pudding-like and wrinkle-like topography portrayed by TEM and SEM. Such features were beneficial to adsorbent recycling and Cd(II) capture. BET examinations illustrated 6.084 m2 g-1 of specific surface area, 0.015 mL g-1 of pore volume, and 6.536 nm of pore diameter. FTIR, VSM, XRD, TEM-SAED, TG, and DTG characterizations were indicative of successful synthesis, satisfactory magnetism, well-defined architecture, and good thermostability. Optimal adsorption parameters for Cd(II) were determined via batch experiments. Thermodynamic parameters and adsorption data fitting implied an exothermic, spontaneous, monolayer, and chemisorption process. XPS analyses confirmed a potential adsorption mechanism that N and O atoms on microparticles chelated with Cd(II) ions in solutions. Additionally, MCS-MA-TEPA-Cd(II) microparticles were magnetically separated easily and had outstanding reusability even after five-time recycling, with a slight adsorption capability loss (< 12%). Altogether, MCS-MA-TEPA microparticles might serve as a promising adsorbent for contaminated water scavenging.

Cr(VI) and Pb(II) capture on pH-responsive polyethyleneimine and chloroacetic acid functionalized chitosan microspheres.

PEI-ECH-CMCS microspheres (MPs) were first constructed via elaborately programmed procedures. Fourier transform infrared spectroscopy, conductometric titration, Brunauer-Emmett-Teller, X-ray diffraction, pH at zero point of charge (pHzpc), scanning electron microscopy, X-ray photoelectron spectroscopy, and swelling results demonstrated that chitosan-based adsorbent had ample -NH2 and -COOH, specific surface area of 29.040 m2/g, porous 3D architectures, pHzpc of 4.2, uniform spherical surfaces, narrow size distribution (19-33 µm), and pH-responsive swelling features, advantageous to Cr(VI) and Pb(II) capture. Adsorption parameters were obtained from batch experiments and pH 3 and 5 were chosen for Cr(VI) and Pb(II) capture. Pseudo-second-order kinetic and Liu isotherm models well interpreted adsorption behavior, and thermodynamic, isotherm, and kinetic studies revealed an exothermic, spontaneous, monolayer, and chemical adsorption process. Maximum adsorption capacity for Cr(VI) or Pb(II) was 331.32 or 302.56 mg/g, exceeding CS-based adsorbents reported. Excellent reusability and feasibility were evidenced by adsorption capacity loss < 12.10% and high removal efficiency for Cr(VI) (95.79%) and Pb(II) (91.40%) in synthetic effluents. Finally, potential adsorption mechanisms were proposed.

The deubiquitylating enzyme USP15 regulates homologous recombination repair and cancer cell response to PARP inhibitors.

Poly-(ADP-ribose) polymerase inhibitors (PARPi) selectively kill breast and ovarian cancers with defects in homologous recombination (HR) caused by BRCA1/2 mutations. There is also clinical evidence for the utility of PARPi in breast and ovarian cancers without BRCA mutations, but the underlying mechanism is not clear. Here, we report that the deubiquitylating enzyme USP15 affects cancer cell response to PARPi by regulating HR. Mechanistically, USP15 is recruited to DNA double-strand breaks (DSBs) by MDC1, which requires the FHA domain of MDC1 and phosphorylated Ser678 of USP15. Subsequently, USP15 deubiquitinates BARD1 BRCT domain, and promotes BARD1-HP1γ interaction, resulting in BRCA1/BARD1 retention at DSBs. USP15 knockout mice exhibit genomic instability in vivo. Furthermore, cancer-associated USP15 mutations, with decreased USP15-BARD1 interaction, increases PARP inhibitor sensitivity in cancer cells. Thus, our results identify a novel regulator of HR, which is a potential biomarker for therapeutic treatment using PARP inhibitors in cancers.

Selective Adsorption toward Hg(II) and Inhibitory Effect on Bacterial Growth Occurring on Thiosemicarbazide-Functionalized Chitosan Microsphere Surface.

The work presented here aims to fabricate dual-purpose adsorbent with adsorption selectivity for Hg(II) and antibacterial activity. TSC-PGMA-MACS microspheres were first constructed via esterification of malic acid (MA) with chitosan (CS) and through successively grafting glycidyl methacrylate (GMA) and thiosemicarbazide (TSC) onto MACS microsphere surfaces. Fourier transform infrared spectroscopy, elemental analysis, energy-dispersive X-ray spectrometry, X-ray diffraction, differential scanning calorimetry, thermogravimetry, differential thermogravimetry, scanning electron microscopy, and Brunauer-Emmett-Teller results provided ample evidence that new mesoporous adsorbent, with 35.340 m2 g-1 of specific surface area and abundant -NH2 and C═S, was successfully fabricated and had loose crystalline, thermodynamically stable, and well-defined architectures, beneficial for Hg(II) adsorption and bacterial cell killing. Optimal adsorption parameters were determined via varying pH, time, concentrations, and temperatures, and pH 6.0 was chosen as an optimal pH for Hg(II) adsorption. Adsorption behavior, described well by pseudo-second-order kinetic and Langmuir isotherm models, and thermodynamic parameters implied a chemical, monolayer, endothermic, and spontaneous adsorption process, and the maximum adsorption capacity for Hg(II) was 242.7 mg g-1, higher than most of the available adsorbents. Competitive adsorption exhibited excellent adsorption selectivity for Hg(II) in binary-metal solutions. Besides, TSC-PGMA-MACS microspheres had outstanding reusability even after five times recycling, with adsorption capability loss <14%. Several potential adsorption sites and bonding modes were proposed. Notably, TSC-PGMA-MACS microspheres before and after adsorption were of high antibacterial activity against Escherichia coli and Staphylococcus aureus (MICs, 2 and 0.25 mg mL-1), superior to CS powders, and possible antibacterial mechanisms were also summarized. Altogether, dual-purpose TSC-PGMA-MACS microspheres might be promising adsorbent for contaminated water scavenging.

Preparation, characterization, and evaluation of 3,6-O-N-acetylethylenediamine modified chitosan as potential antimicrobial wound dressing material.

This work aims to prepare 3,6-O-N-acetylethylenediamine modified chitosan (AEDMCS) and evaluate its potential use as an antimicrobial wound dressing material. UV, FTIR, and 1H NMR results demonstrated N-acetylethylenediamine groups were successfully grafted to C3OH and C6OH on polysaccharide skeletons. TGA, XRD, and solubility tests indicated that as compared with chitosan, AEDMCS had diminished thermostability, decreased crystallinity, and greatly improved solubility. AEDMCS, with degrees of deacetylation and substitution being respectively 90.3% and 0.72, exhibited higher antibacterial activity than chitosan against six bacteria generally causing wound infections. Meanwhile, AEDMCS had permissible hemolysis and cytotoxicity and low BSA adsorption even at a AEDMCS concentration of 25mg/mL. Acute toxicity tests showed AEDMCS was nontoxic. Moreover, the wound healing property was preliminarily evaluated, illustrating that AEDMCS enhanced wound healing rates as expected and had no significant differences as compared with chitosan. These results suggested AEDMCS might be a potential material used as antibacterial wound dressings.

Characterization and antibacterial mechanism of poly(aminoethyl) modified chitin synthesized via a facile one-step pathway.

This work aims to synthesize poly(aminoethyl) modified chitin (PAEMC) and ascertain its antibacterial activity and mechanism. FTIR and 1H NMR results proved aminoethyl moieties were grafted to C6OH and C3OH on chitin backbone in the form of polymerization. XRD and TG/DTG analyses manifested its well-defined crystallinity and thermostability. PAEMC, with average molecular weight (MW) of 851.0 kDa, degree of deacetylation (DD) of 27.95%, and degree of substitution (DS) of 1.77, had good solubility in aqueous solutions over the pH range of 3-12, and also possessed high antimicrobial activity against Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus proteus, and Klebsiella pneumoniae, commonly causing chronic wound infections. Nucleic acid release, protein leakage, increased inner membrane permeability, and decreased cell surface hydrophobicity implied bacterial cytomembranes were substantially compromised in the presence of PAEMC. Microscopically, PAEMC visually perturbed bacteria, illustrating deformed and even collapsed morphologies. Overall, PAEMC possessed good solubility, effectively destroyed bacteria via a membrane damage mechanism, and might serve as an antibacterial agent for treatments of chronic wound infections.

Uptake of Pb(II) and Cd(II) on Chitosan Microsphere Surface Successively Grafted by Methyl Acrylate and Diethylenetriamine.

A novel adsorbent, CS-MA-DETA microspheres, for uptake of heavy metal ions from aqueous solutions was first fabricated via two-step grafting methyl acrylate (MA) and diethylenetriamine (DETA) onto chitosan (CS) microsphere surface in the absence of cross-linkers. CS-MA-DETA microspheres of 3.04 µm in mean diameter were of uniformly wrinkle-like topography sketched out by SEM, whose surface after decoration by MA and DETA was stable and beneficial to metal ion capture. Its chemical composition, microstructure, and thermal property were characterized by elemental analysis, FTIR, XRD, BET, and TGA techniques, and the achieved quantitative results mainly included C/N ratio (4.76), crystallinity (31.20%, 19.75% of CS), specific surface area (27.806 m2 g-1), pore diameter (3.452 nm), and mass loss at the first stage (3%, around 10% of CS), which indicated a successful synthesis, well-defined structure, and good thermostability. Adsorption tests of CS-MA-DETA microspheres were performed in Pb(II) and/or Cd(II) solution(s) at various pH values, contact time, and initial concentrations, exhibiting an excellent adsorption capability. Its maximum adsorption capacity calculated by Langmuir model was 239.2 mg Pb(II)/g, or 201.6 mg Cd(II)/g, which was higher than those of most available CS-based adsorbents. Furthermore, several adsorption kinetic and isotherm models were employed to investigate its uptake behavior, implying that it was mainly a monolayer adsorption and chemisorption process. Five-cycle reusability tests demonstrated CS-MA-DETA microspheres could be repeatedly used without significant capacity loss (<10%). Additionally, several potential bonding modes and adsorption sites for both metal ions were also proposed. Overall, CS-MA-DETA microspheres with outstanding adsorption performance toward Pb(II) and/or Cd(II) might serve as a new absorbent for wastewater purification.

Preparation and characterization of poly(maleic acid)-grafted cross-linked chitosan microspheres for Cd(II) adsorption.

A novel adsorbent, composed of poly(maleic acid)-grafted cross-linked chitosan microspheres (PMACCMs), was prepared via cross-linking with glutaraldehyde and modification by grafting maleic acid. FTIR, zeta potential, elemental analysis, 13C NMR, DTG, laser particle size analysis, SEM, and BET methods were applied to characterize PMACCMs, exhibiting a successful fabrication, good thermostability, and well-defined surface microstructure beneficial to Cd(II) adsorption. The effects of pH, contact time, and initial concentration on Cd(II) adsorption were also investigated, and the maximum adsorption capacity was 39.2mgg-1, indicating a great improvement as compared with that (14.5mgg-1) of cross-linked chitosan microspheres. The experimental data were well fitted with pseudo-second-order kinetic and Langmuir isotherm models. Five-cycle reusability tests demonstrated PMACCMs could be repeatedly used with a small adsorption capacity loss (<15%). Additionally, the adsorption mechanism was proposed. All the results confirmed that PMACCMs, which presented outstanding adsorption capability and reusability, could be a good candidate for wastewater purification.

Itaconic acid grafted carboxymethyl chitosan and its nanoparticles: Preparation, characterization and evaluation.

This work aims to synthesize a novel itaconic acid (IA) grafted carboxymethyl chitosan (PICMCS), and further fabricate its nanoparticles for potential biomedical applications. First, PICMCS was prepared via free-radical polymerization of IA monomer, in the presence of ammonium persulfate as an initiator and nitrogen as a protector. Its chemical structure was confirmed by FTIR and 1H NMR. The IA substitution degree calculated by elemental analysis data was 1.85, implying that IA was successfully grafted to carboxymethyl chitosan (CMCS). XRD and TGA patterns illustrated its well-defined crystallinity and thermostability. Second, PICMCS nanoparticles were fabricated by electrostatic attraction between carboxyl and amino groups in the absence of any additional agent, which were of obvious core-shell structures with an average particle size of 144nm and a polydispersity index of 0.11. PICMCS nanoparticles exhibited excellent physical stability after storage at 25°C for 30days, without any aggregation. PICMCS nanoparticles with high negative surface charge also indicated the good stability, especially in neutral or alkaline media. Additionally, the cytotoxicity experiments showed that either PICMCS or its nanoparticles had better cytocompatibility toward L929 cells than CMCS. These findings above suggested that PICMCS was a kind of promising material for preparing nanoparticles used in biomedical field.

Synthesis, characterization, and evaluation of poly(aminoethyl) modified chitosan and its hydrogel used as antibacterial wound dressing.

This study aims to develop new antibacterial hydrogel wound dressings composed of poly(aminoethyl) modified chitosan (PAEMCS). FTIR, 1H NMR, and elemental analysis demonstrated that PAEMCS was successfully synthesized via grafting poly(aminoethyl) groups onto hydroxyl groups on chitin first, and removing acetyl groups from the grafted polymer afterward. XRD and TGA implied its well-defined crystallinity and thermostability. Furthermore, a series of hydrogels were fabricated under the participation of dipotassium hydrogen phosphate (DHP). The gelation tests suggested that the higher concentration of PAEMCS or DHP was beneficial to the formation of hydrogels. The pH values of hydrogels at 37°C were all in the range of 7.12-7.50. The rheological tests indicated that PAEMCS-based hydrogels were of lower DHP addition and higher elasticity than CS-based hydrogels to achieve the same gelation temperature under the same polymer's concentration. Additionally, the swelling, anti-bacteria, and cytotoxicity experiments showed that PAEMCS-based hydrogels possessed excellent hygroscopicity, high antibacterial activity against E. coli, S. aureus, or S. epidermidis, and good cytocompatibility toward L929 cells or HUVECs, respectively. All the results implied that PAEMCS-based hydrogels not only maintained inherent multiple properties of chitosan but also possessed excellent antibacterial activity, and might be promising antibacterial hydrogel dressings used in wound therapy.