Percentage Of Grafting Research Articles

Hyaluronic Acid Based Azo Polymer: Synthesis, Characterization, and Photo‐Responsiveness

AbstractHyaluronic acid based azo polymer (HA‐Azo‐COOH) is synthesized by post‐azo coupling reaction. Controllable grafting percent of azobenzene pendant is achieved by adjusting the feed ratio. In selective solvents (dimethyl sulfoxide/water), uniform colloidal aggregates of the prepared polymer can be obtained by self‐assembly process. The self‐assembled colloids can be elongated along the polarization direction of the irradiation laser light. The relationship between the deformation of colloids and the irradiation time is explored.

Fascinating Pathway to Facilitate the Photoisomerization of Spiropyran-Based Nanocomposites.

Recently, spiropyran-based composites have gained more attention on account of their stimuli-responsive essence, especially of the fascinating and green photo stimulus. However, the great dipole moment change between the ring-opened merocyanine and ring-closed spiropyran requires a large free volume available for isomerization, which significantly restrains the photoisomerization of spiropyran-based nanocomposites. Herein, a fascinating pathway by regulating the states both of spiropyran and the immobilized nanoparticle supports was put forward to facilitate the photoisomerization. The results demonstrated that the spiropyran grafting percentage of 5.18% and immobilized supports with less aggregation, high specific surface area, large pore size, and noncrystalline structure were suitable to fabricate spiropyran-based nanocomposites, which showed a significant improvement for Pb2+ and Cr3+ removal from aqueous solution on account of free photoisomerization of spiropyran on the support's surface. This work will pave the pathway to extend the exploitation of spiropyran-based nanocomposites in various fields such as biotechnology, physiology, and electronics to photonics and environmental-friendly fields.

Modification of Poly(Glycerol Adipate) with Tocopherol and Cholesterol Modulating Nanoparticle Self-Assemblies and Cellular Responses of Triple-Negative Breast Cancer Cells to SN-38 Delivery.

This study aimed to fabricate new variations of glycerol-based polyesters by grafting poly(glycerol adipate) (PGA) with hydrophobic bioactive moieties, tocopherol (TOC), and cholesterol (CHO). Their effects on nanoparticle (NP) formation, drug release, and cellular responses in cancer and normal cells were evaluated. CHO and TOC were successfully grafted onto PGA backbones with 30% and 50% mole grafting. Increasing the percentage of mole grafting in both molecules increased the glass transition temperature and water contact angle of the final polymers but decreased the critical micelle concentration of the formulated particles. PGA-TOC NPs reduced the proliferation of MDA-MB-231 cancer cells. However, they enhanced the proliferation of primary dermal fibroblasts within a specific concentration range. PGA-CHO NPs minimally affected the growth of cancer and normal cells. Both types of NPs did not affect apoptosis or the cell cycle of cancer cells. PGA-CHO and PGA-TOC NPs were able to entrap SN-38, a hydrophobic anticancer drug, with a particle size <200 nm. PGA-CHO NPs had a higher drug loading capacity and a greater drug release than PGA-TOC NPs. However, SN-38-loaded PGA-TOC NPs showed higher toxicity than SN-38 and SN-38-loaded PGA-CHO NPs due to the combined effects of antiproliferation and higher cellular uptake. Compared with SN-38, the drug-loaded NPs more profoundly induced sub-G1 in the cell cycle analysis and apoptosis of cancer cells in a similar pattern. Therefore, PGA-CHO and PGA-TOC polymers have potential applications as delivery systems for anticancer drugs.

Okra-psyllium based green synthesis of eco-friendly bio-adsorbent for efficient removal of uranium and crystal violet dye from aqueous media: statistical optimization using response surface methodology

Abstract The prime objective of this study is to synthesize eco-friendly okra-psyllium based hydrogel through free radical crosslinking method by using citric acid-ammonium persulfate as a crosslinker-initiator system. Various techniques were used to explore the morphology, structure and thermal behaviour of the synthesized hydrogel via. Powdered X-ray diffraction studies, SEM and TGA techniques. Response surface methodology was performed to maximize the grafting percentage of the synthesized hydrogel up to 244 % and swelling percentage of 598 %. The physicochemical properties like salt-resistance behaviour and the impact of ionic strength on the swelling percentage of synthesized hydrogel were investigated and thus observed with the following trend as K+ &gt; Ca2+ &gt; Fe3+. Furthermore, the synthesized sample showed an excellent bio-adsorbent behaviour for the removal of uranium with 97.75 % removal in 60 min and crystal violet dye removal up to 85.32 % in 24 h from contaminated water. Various kinetic and isotherm adsorption modelling were implied to probe the mechanism of adsorption with displayed interactions between the absorbate and the absorbent. The Langmuir isotherm model was well-fitted in dye adsorption case with regression co-efficient value of 0.99. In case of uranium, tempkin isotherm model was best fitted with regression co-efficient value as 0.92. Crystal violet dye adsorption favoured second-order kinetic model whereas the adsorption mechanism of uranium followed first-order kinetics. Hence, the revealed results depicted that the synthesized hydrogel served as a potential candidate for the effective removal of toxic dye (crystal violet) and metal ion (uranium) from aqueous media with a sustainable approach towards environment.

Photocrosslinkable gelatin-treated dentin matrix hydrogel as a novel pulp capping agent for dentin regeneration: I. synthesis, characterizations and grafting optimization

BackgroundIn recent years, treated dentin matrix (TDM) has been introduced as a bioactive hydrogel for dentin regeneration in DPC. However, no study has introduced TDM as a photocrosslinkable hydrogel with a natural photoinitiating system. Therefore, the present study aimed to explore the synthesis, characterizations and grafting optimization of injectable gelatin- glycidyl methacrylate (GMA)/TDM hydrogels as a novel photocrosslinkable pulp capping agent for dentin regeneration.MethodsG-GMA/TDM hydrogel was photocrosslinked using a new two-component photoinitiating system composed of riboflavin as a photoinitiator under visible light and glycine as a first time coinitiator with riboflavin. The grafting reaction conditions of G-GMA/TDM e.g. GMA concentration and reaction time were optimized. The kinetic parameters e.g. grafting efficiency (GE) and grafting percentage (GP%) were calculated to optimize the grafting reaction, while yield (%) was determined to monitor the formation of the hydrogel. Moreover, G-GMA/TDM hydrogels were characterized by swelling ratio, degradation degree, and cytotoxicity. The instrumental characterizations e.g. FTIR, 1H-NMR, SEM and TGA, were investigated for verifying the grafting reaction. Statistical analysis was performed using F test (ANOVA) and Post Hoc Test (P = 0.05).ResultsThe grafting reaction dramatically increased with an increase of both GMA concentration and reaction time. It was realized that the swelling degree and degradation rate of G-GMA/TDM hydrogels were significantly reduced by increasing the GMA concentration and prolonging the reaction time. When compared to the safe low and moderate GMA content hydrogels (0.048, 0.097 M) and shorter reaction times (6, 12, 24 h), G-GMA/TDM with high GMA contents (0.195, 0.391 M) and a prolonged reaction time (48 h) demonstrated cytotoxic effects against cells using the MTT assay. Also, the morphological surface of G-GMA/TDM freeze-dried gels was found more compacted, smooth and uniform due to the grafting process. Significant thermal stability was noticed due to the grafting reaction of G-GMA/TDM throughout the TGA results.ConclusionsG-GMA/TDM composite hydrogel formed by the riboflavin/glycine photoinitiating system is a potential bioactive and biocompatible system for in-situ crosslinking the activated-light pulp capping agent for dentin regeneration.

Comparative study of outcomes between application of negative pressure wound therapy to split skin graft versus split skin graft immobilized by traditional bolster dressing

Background: SSG is a versatile technique used for the reconstruction of wounds. The conventional techniques like traditional bolster dressing (TBD) to secure graft have been in use since the long time for the management of these wounds. NPWT is an effective advanced therapy which increase graft take by providing negative pressure to seal the space and provide persistent and uniform pressure. Methods: 60 patients were enrolled in the study. In the TBD group (30 patients) a bolster was placed on the graft which was made using a nonadherent dressing. In the NPWT group (30 patients) the SSG was secured using circumferential staples, followed by placement of VAC dressing with continuous negative pressure. Percentage of graft take assessed on 5th, 7th and 9th postop day. Results: Graft take on day 5th with NPWT group was 83.16±4.1% and in TBD group was 78.12±3.76%. On day 7th with NPWT group was 89.83±4.12% and in TBD group was 84.33±4.66%. On Day 9th with NPWT group was 96.33±5.3% and in TBD group was 92.67±5.24%. In NPWT group, mean Post SSG days were 9.9±0.61days. In TBD group, mean Post SSG days were 13.03±1.4 days. Conclusions: Our study suggest that Application of NPWT on SSG is beneficial in terms of better graft take, lesser infection, shortened post graft hospital stays and less no who needs for redo SSG and it is particularly useful anatomically challenging sites.

Polyaniline grafted pullulan: Optical, thermal, structural, and electrical characterization studies in combination withdensity functional theorycalculations

AbstractPolyaniline (PANI), a conducting polymer, has great interest for a large number of applications. However, poor processability and mechanical properties limits its usage and many methods like blending, grafting etc. are used to overcome this disadvantage. We have carried out grafting of PANI onto pullulan (PULL) via chemical oxidative polymerization technique. The percentage of grafting is favored by increasing concentration of aniline monomer. The formation of PANI is confirmed through UV–Vis spectroscopic studies. The possible grafting mechanism is studied using Fourier transform infrared spectroscopy and validated by Hartree‐Fock density functional theory (HF‐DFT) calculations. Further, thermal properties of grafted polymers are studied using differential scanning calorimetry and thermo gravimetric analysis. Using FESEM and x‐ray diffraction, structural properties of graft polymer were studied. DC electrical conductivity of grafted polymer is measured from I‐V characteristics, shows a significant conductivity which is the highlight of this work.

Continuous-Flow Grafting of LENFLOC™ Coagulant for Water Treatment toward Circular Economy

This study investigated the efficiency of LENFLOC™ production using a microwave-assisted continuous-flow grafting process. The study discussed the contribution of plant-based coagulants for water and wastewater treatment toward the circular economy in water treatment. Lentil waste extract was used to produce LENFLOC™ using (2-methacryloyloxyethyl) trimethyl ammonium chloride with 75 wt.% on H2O as a chain monomer and cerium ammonium nitrate (≥98%) as an initiator. The continuous flow grafting process was conducted at a constant flowrate of 60 mL/min and reaction time of 30 s. The process was optimised using RSM to obtain optimum conditions of process factors. Characterisation studies were conducted using Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. A comparison study was performed using a Jar test with LENFLOC™, lentil waste extract, and a polymer as coagulants. The results obtained show that the continuous-flow grafting process was efficient with an optimum grafting percentage of 330%. The characterisation studies confirmed the grafting process. A 99% turbidity removal rate was achieved with LENFLOC™ as a coagulant with a lower dosage compared to the lentil waste extract. Furthermore, microscope imaging showed improved floc compaction when using LENFLOC™ as a coagulant. The continuous-flow grafting process has been shown to be effective; therefore, its potential for upscaling the process is possible.

Ossification and Bone Regeneration in a Canine GBR Model, Part 1: Thick vs Thin Glycated Cross-Linked Collagen Devices.

Purpose: To compare glycated multilayered membranes (OV) to a commercially available thin-layer membrane (OP) in a lateral ridge augmentation model in dogs. Materials and Methods: This was designed as a three-arm study, where one negative control (empty defect) was compared to two test arms: alveolar bone defects grafted with a mixture of 90% deproteinized bovine bone mineral and 10% porcine collagen, then covered with either a thick- (OV) or thin-layered (OP) membrane. Animals were randomly divided into three groups corresponding to the final sacrifice times of 4 weeks, 12 weeks, and 24 weeks. Sections underwent microCT, histology, histopathology, and histomorphometry. Results: No statistical differences were observed for OV compared to OP regarding the percentage of mineral volume and mean mineral density, amount of bone maturation, percentage of bone graft and membrane remaining in the grafted area, alveolar ridge width measurements, membrane mineralization, or ossification. Test groups presented significantly higher values compared to the empty control for all the endpoints. Conclusions: Within its limitations, this in vivo study highlighted that multilayered thick glycated membranes can serve as effective occlusive barriers for up to 6 months.

Grafting of branched polyethyleneimine onto carbon nanotubes to efficiently enhance the lap shear strength of epoxy adhesives

In this study, the lap shear strength of the epoxy-based adhesive was significantly enhanced by incorporating branched polyethyleneimine dendrimer (PEI) functionalized carbon nanotubes (CNTs) and a phase-separated triblock copolymer. The level of PEI grafting was controlled by adjusting the CNT to PEI dispersion ratio from 1:0.1 up to 1:5, which led to grafting percentages ranging from 5% to 51%. The lap shear strength was increased significantly for all PEI treatments with an optimum increase of 122% for a grafting ratio of 1:1 compared to unmodified epoxy. At lower grafting ratios, the PEI led to a narrow distribution of lower average lap shear strength. The thinner PEI coating was less efficient at dispersing the CNT and fully reacting with the epoxy matrix. The highest grafting ratios improved the dispersion of the CNT and enabled much higher loading in the epoxy. However, at these high PEI concentrations, heterogeneous curing reactions evolved which created localised stress concentrations under loading, causing a reduction in the lap shear strength. This is the first study where PEI grafting levels have both been optimized in CNT and triblock copolymer adhesives and also directly related to adhesive shear strength based on chemical and morphological changes.

Estimation of wound surface area: an evaluation of medical professionals' assessment in a plastic surgery unit.

The percentage of skin graft take following the resurfacing of burn injuries is routinely calculated in a subjective fashion, in order to make management decisions. Given the gravity of decisions made based on this clinical assessment of graft check, it is notable that limited research has been carried out on this subject. No standardised subjective assessment tools exist to measure surface area of graft take in a manner similar to that of Wallace's Rule of Nines or Lund and Browder. This study set out to examine the accuracy of visual assessments of graft take within the multidisciplinary team regularly making assessments of newly grafted burn wounds. A total of 15 digitally drawn images were used to assess 36 staff members' estimations of percentage of surface area. The results showed a wide variation in estimation in all staff types, including senior burns surgeons, who were found to underestimate surface area by as much as 30%. The British Burns Association has removed 'healing time' as an outcome measurement from its guidance, as it recognises how hard it is to make a standardised assessment of wound healing. This study demonstrates the difficulty in subjectively assessing surface area and makes some suggestions for further research and clinical applications of technology to aid assessment.

Microwave-assisted Synthesis and Characterization of Acrylamide Grafted Copolymer of Okra Gum with the Application of 32 Central Composite Designs (CCD)

Introduction: Modified polymeric materials are nowadays most commonly used for making modified release pharmaceutical dosage forms. Methods: In this present research study, a grafted copolymer is synthesized by using acrylamide and okra gum with the help of the redox initiator method. The method was optimized using a 3-factor, 2-level central composite design (CCD). Optimization of the synthetic process was done by the application of QbD, amount of acrylamide (1-10g), amount of initiator (50-150 mg), and microwave irradiation exposure time (1-5 min) were taken critical process variables and response factors were selected as percentage grafting (% grafting) and percentage yield (% yield). Results and Conclusion: The optimized formulation (F13) having a maximum percentage of grafting 82.2 and a percentage yield of 12.54 of the formulation’s acrylamide (5.5g), amount of initiator (100 mg), and microwave irradiation exposure time (3 min). Characterization of synthesized grafted copolymer product was performed by using differential scanning calorimetry (DSC), FT-IR spectroscopy, and scanning electron microscopy (SEM).

Sodium Salt of Partially Carboxymethylated Sodium Alginate-g-Poly(acrylonitrile): I. Photo-Induced Synthesis, Characterization, and Alkaline Hydrolysis.

An efficient redox initiating system, ceric ammonium nitrate/nitric acid, has been employed for the first time to carry out photo-induced graft copolymerization of acrylonitrile (AN) onto sodium salt of partially carboxymethylated sodium alginate, having an average degree of substitution value to be 1.10. The photo-grafting reaction conditions for maximum grafting have been systematically optimized by varying the reaction variables such as reaction time, temperature, the concentration of acrylonitrile monomer, ceric ammonium nitrate, and nitric acid, as well as the amount of the backbone. The optimum reaction conditions are obtained with a reaction time of 4 h, reaction temperature of 30 °C, acrylonitrile monomer concentration of 0.152 mol/L, initiator concentration of 5 × 10-3 mol/L, nitric acid concentration of 0.20 mol/L, amount of backbone of 0.20 (dry basis) and the total volume of the reaction system of 150 mL. The highest percentage of grafting (%G) and grafting efficiency (%GE) achieved are 316.53% and 99.31%, respectively. The optimally prepared graft copolymer, sodium salt of partially carboxymethylated sodium alginate-g-polyacrylonitrile (%G = 316.53), has been hydrolyzed in an alkaline medium (0.7N NaOH, 90-95 °C for ~2.5 h) to obtain the superabsorbent hydrogel, H-Na-PCMSA-g-PAN. The chemical structure, thermal characteristics, and morphology of the products have also been studied.

Experimental studies on the preparation and properties of starch‐graft‐poly(hexyl acrylate) copolymers

AbstractThe preparation and the properties such as the chemical stability, solution properties, moisture absorption, ability to gelation, glass transition temperatures, thermal stabilities and the decomposition course of starch‐graft‐poly(hexyl acrylate) copolymers have been studied. In general, it can be said that as the grafting percent increases the chemical resistance in alkaline, inert, acidic and buffer environments, and the solubility in non‐polar solvents of the copolymers increases. In turn, the solubility in polar solvents decreases compared to the solubility of starch. The Tg of starch‐g‐poly(hexyl acrylate) copolymers is in the range 102–133°C and is much higher than Tg of poly(hexyl acrylate) homopolymer. The thermal stability of all tested copolymers is higher than 274°C (inert conditions) and 230°C (oxidative conditions). In inert conditions, all tested copolymers decompose in two main stages related to pyrolysis combined with the emissions of the following volatiles: CO, CO2, H2O, aldehydes, alcohols, acids, ester, furanes, aliphatic and alkene fragments. In turn, the copolymers decompose in main three stages in oxidative conditions. The emission of CO, CO2, H2O, aldehydes, alcohols, acids, aliphatic, furanes and alcohols as a result of pyrolysis, oxidation, decarboxylation, dehydration, and combustion processes was confirmed.

Development of polylactic acid based antimicrobial food packaging films with N-halamine modified microcrystalline cellulose

Bio-based “green” films with superior antimicrobial activity were developed from polylactic acid (PLA) and cyclic N-halamine 1-chloro-2,2,5,5-tetramethyl-4-imidazolidinone (MC) grafted microcrystalline cellulose (MCC) fibers (herein referred to as g-MCC). The structure of g-MCC was characterized by Fourier Transform Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR) spectroscopy. Results indicated N-halamine MC was successfully grafted onto MCC fibers, with a grafting percentage of 10.24 %. The grafting improved compatibility between g-MCC and PLA, leading to an excellent dispersion of g-MCC in the film matrix, and a superior transparency of the g-MCC/PLA compared to that of the MCC/PLA films. Additionally, the enhanced compatibility the g-MCC/PLA films produced better mechanical properties including mechanical strength, elongation at break and initial modulus than those of both MCC/PLA and MC/PLA composites. With N-halamine, g-MCC/PLA completely inactivated all the inoculated Escherichia coli and Staphylococcus aureus within 5 and 30 min of contact, respectively. More importantly, the migration test showed that the oxidative chlorine of g-MCC/PLA was highly stable than that of MC/PLA films, providing a long-term antimicrobial activity. Finally, preservation test conducted on fresh bread slices further demonstrated its promising applications in the food industry.

Reactive compatibilization of polypropylene grafted with maleic anhydride and styrene, prepared by a mechanochemical method, for a blend system of biodegradable poly(propylene carbonate)/polypropylene spunbond nonwoven slice

Abstract Poly(propylene carbonate) (PPC)/polypropylene (PP) spunbond nonwoven slice has gained more attention, owing to its excellent properties, such as biodegradability, flexibility, biocompatibility, and CO2 utilization. However, the applications of this green material are limited due to the poor thermodynamic incompatibility between PPC and PP. In this paper, PP grafted with maleic anhydride (MAH) and styrene (St) (PP-g-(MAH-co-St)), prepared by a mechanochemical method and having a grafting percentage G MAH = 1.40 %, was used as a compatibilizer to prepare a biodegradable PPC/compatibilizer/PP composite-spunbond nonwoven slice by melt-blending. The effects of compatibilizer content on the tensile strength, elongation at break, melt flow rate, thermal properties, and micro-morphology of PPC/PP-g-(MAH-co-St)/PP were systematically studied. Furthermore, the mechanism of compatibilization of PP-g-(MAH-co-St) in the PPC/PP spunbond nonwoven composite slice is discussed. The results indicated that this green PP-g-(MAH-co-St) exhibited a clear reactive compatibilization effect. Therefore, it can be considered as a good compatibilizer for the biodegradable PPC/PP spunbond nonwoven slice.

Deceased donor vein extension grafts for right living donor kidney transplantation.

In an effort to maximize living donor kidney utilization, we describe the use of deceased donor vein extension grafts for right-sided living donor kidneys and report our single-center experience using this technique. A retrospective review of kidney transplant recipients (KTR) who received a right living donor kidney with deceased donor vein extension graft. Recipient demographics, postoperative graft function, and surgical complications were reviewed. Living donor nephrectomies were performed laparoscopically. Vein grafts were obtained from recent deceased donor procurements. End-to-end anastomosis of the graft to the renal vein was performed prior to implantation. Thirty-eight KTR received a right kidney transplant with deceased donor extension grafts. The median recipient age and BMI were 53.0 years and 29.3kg/m2 . Total 71% were male. Ninety-five percent of grafts displayed immediate graft function, with two recipients requiring temporary dialysis due to anaphylaxis from induction therapy. Median serum creatinine at two weeks was 1.6mg/dL and at three months was 1.5mg/dL. There were no graft thromboses. Utilization of deceased donor extension grafts for short right renal veins is a simple technique that expands the donor pool for living donor renal transplantation. Our experience resulted in no technical complications and excellent early graft function.

Surface modification of silica with polymethylmethacrylate‐co‐methacrylic acid for enhancement of self‐healing performance of natural rubber composites based on metal thiolate ionic network

AbstractPolymethylmethacrylate‐co‐methacrylic acid (PMMA‐co‐MAA) was utilized for surface improvement of silica to be used as reinforcement in self‐healing natural rubber based on metal thiolate ionic network. The amount of PMMA‐co‐MAA was varied at 1, 3, and 5 wt% of silica content and the optimized PMMA‐co‐MAA was utilized to investigate the self‐healing NR/silica composites at different filler loading (5, 10, 20, and 30 phr). The graft polymerization of PMMA‐co‐MAA on silica was confirmed using FTIR spectroscopy and grafting percentage was determined by thermogravimetric analysis (TGA). Intermolecular diffusion occurred at the fractured area was detected using a scanning electron microscope (SEM) and the results revealed that the composite tensile and tear performance increased 22%–70% with healing efficiency percentage ranging between 70% and 97% depending on the silica loading.

Does preoperative glenoid bony defect determine final coracoid graft positioning in arthroscopic Latarjet?

It has been demonstrated that the accurate positioning of the graft is key to restoring shoulder stability and preventing future arthrosis development. Preoperative anteroinferior glenoid bone loss is frequently encountered when performing a Latarjet, and it has not been determined yet if the amount of bony defect can influence graft positioning. The aim of the study was to determine if a preoperative glenoid bony defect has an influence on the final coracoid graft position in the arthroscopic Latarjet procedure. Fifty-five patients who underwent the arthroscopic Latarjet procedure were included, with a minimum follow-up of 2 years. There were 51 men (92.7%). Mean age was 29.1 (SD 7.63). Western Ontario Shoulder Instability Index, Rowe, and Single Assessment Numeric Evaluation scores were fulfilled. All measurements were performed by a musculoskeletal radiologist based on a multiplanar bidimensional CT scan. Dimensions of the glenoid, glenoid defect, and glenoid track were calculated. Position of the graft was evaluated in the axial (distance to glenoid surface, angulation of the graft and screws) and sagittal planes (percentage of the coracoid graft below the equator) as described by Kany etal and Barth etal respectively. There was a glenoid defect in 41 patients (74.5 %). Mean width of the defect was 4.32 mm (SD 3.08) which represented 15.3% of the native glenoid surface (SD 10.8). 78.2% of the patients were offtrack preoperatively, and 11.9% remained offtrack postoperatively. The final glenoid diameter with the graft was 32.1 mm (SD 4.34). Mean distance from the graft to the glenoid at 50% height was 1.1 mm (SD 2.19 mm) and at 25% height was 1.31 mm (SD 2.05). Mean angulation of the superior and inferior screws were 26.9° (SD 8.2°) and 27.1° (SD 7.35°), respectively. In 81.8% of the cases, the graft was deemed to be flush with the glenoid. The percentage of the coracoid graft under the equator of the glenoid was 71.2 % (SD 21.8). There was not a statistically significant difference in screw angulation or graft positioning in the axial plane when comparing patients who had a glenoid defect with those who did not, or depending on the size (P>.05). Percentage of graft below the equator was, however, lower in patients without bony defect (P=.04). This study showed that accurate position of the coracoid graft is achieved in the presence of a glenoid bony defect. In the cases of intact glenoid, the height of the graft should be carefully evaluated.

Chemical modification of κ-carrageenan with poly(2-hydroxypropylmethacrylamide) through microwave induced graft copolymerization: Characterization and swelling features

In the last decade, interest in the development of new graft copolymers based on natural polysaccharides has grown remarkably due to their potential applications in the wastewater treatment, biomedical, nanomedicine, and pharmaceutical fields. Herein, a novel graft copolymer of κ-carrageenan with poly(2-hydroxypropylmethacrylamide) (κ-Crg-g-PHPMA) was synthesized using a ‘microwave induced’ technique. The synthesized novel graft copolymer has been well characterized in terms of FTIR, 13C NMR, molecular weight determination, TG, DSC, XRD, SEM, and elemental analyses, taking κ-carrageenan as a reference. The graft copolymers' swelling characteristics were investigated at pH 1.2 and 7.4. The results of swelling studies displayed that the incorporation of PHPMA groups on κ-Crg provides increasing hydrophilicity. The effect of PHPMA percentage in the graft copolymers and pH of the medium on the swelling percentage was studied and the findings exhibited that swelling ability increased with the increment in PHPMA percentage and pH of the medium. The best swelling percentage was attained at pH = 7.4 and a grafting percentage of 81 % reaching 1007 % at the end of 240 min. Moreover, cytotoxicity of the synthesized κ-Crg-g-PHPMA copolymer was assessed on the L929 fibroblast cell line and obtained to be non-toxic.