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This research addresses the need for enhanced biomaterials by investigating the influence of the NCO/OH ratio on sodium alginate-based polyurethane elastomers(Al-PUEs), offering novel insights into their structural, thermal, mechanical and swelling behavior. Al-PUEs were prepared by blending the chain extenders with key ingredients in a specific molar ratio using aliphatic HMDI and HTPB monomers. The chemical linkages, crystalline behavior, homogeneity, and surface morphology of PUEs were evaluated by FT-IR, XRD, SEM, and EDX analysis. Thermo-mechanical studies were performed using TGA, DSC and tensile testing. Swelling behavior and absorption analysis were analyzed in DMSO and water. The analysis indicated that the hydrophilicity and swelling behavior of the prepared PUEs were affected by the addition of sodium alginate content. The results exhibit the tailor-made network structure of Al-PUEs, resulting in better thermal stability, elasticity of materials via stress-strain behavior and marvelous characteristic features than traditional high-tech yields. Furthermore, the resulting Al-PUEs are potential candidates for biomedical implants., Competing Interests: Declaration of competing interest On behalf of all my co-authors I hereby declare that we have no conflict of interest for the manuscript being submitted for publication to the journal “International Journal of Biological Macromolecules”., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Face cups form a vital component of breathing, assisting with devices that aid in artificial breathing for neonates. This study aims to evaluate the flow parameters in the nasal cavity for two different types of face cups. The neonatal nasal cavity model was developed from CT scans using MIMICS 21.0. Two face cups, one hemispherical and the other anatomical shaped cups are developed around the nasal cavity and the airflow is simulated using ANSYS 2021 R2. Results are compared with a nasal-only model. At the nasal valve region, the highest velocity is seen for the nasal-only model which is 16.3% higher than that of the hemispherical face cup and 15.2% superior to the anatomical-shaped face cup. In addition, the decrease in pressure across the nasal-only model is 7.4 and 6.6% below that of the hemispherical cup and anatomical cup masks. The nasal resistance values across the nasal cavity are the lowest for the nasal-only model, 7.7 and 6.7% lower respectively than the hemispherical and anatomical-shaped cups. There were very minor changes in the flow parameters such as velocity, pressure and wall shear stress when comparing the hemispherical and anatomic-shaped masks for the airflow inside the nasal cavity.

Understanding the apical pressure and irrigant flow patterns in root canals is crucial for safe and effective irrigation. Therefore, this study aimed to assess the flow characteristics of irrigants in root canal models with varying tapers during final irrigation by employing various needle designs, including a back-to-back double-side-vented needle, through computational fluid dynamics. The root canal model was configured as a closed geometrical cone with a simulated apical zone (size 30) and features tapers of 4%, 6%, and 8%. Three needle types-open-ended needle (OEN), single side-vented needle (SSVN), and double side-vented needle (DSVN)-were investigated. The results indicated that for the 4% taper models, the open-ended needle generated the maximum apical pressure, followed by the double side-vented needle and the single side-vented needle. However, in the 6% and 8% tapering root canal models, the double-side-vented needle applied the lowest maximum apical pressure. Consequently, the DSVN can pose a risk for irrigant extrusion in minimally prepared canals due to heightened apical pressure. In wider canals, the DSVN exhibited lower apical pressure. The maximum irrigant replacement was observed with OEN compared to that of the closed-ended group for both flow rates. Additionally, compared with OENs, closed-ended needles exhibited nonuniform and lower shear wall stress., (© 2024. The Author(s).)

The selection of abrasive material and parameters of the Air-Abrasion device for a particular application is a crucial detail. However, there are no standard recommendations or manuals for choosing these details; the operator must depend on his experience and knowledge of the procedure to select the best possible material and set of parameters. This short review attempts to identify some of the effects that the selection of material and parameters could have on the performance of the Air-Abrasion procedure for a particular application. The material and parameter data are collected from various studies and categorized according to the most popular materials in use right now. These studies are then analyzed to arrive at some inferences on the performance of Air-Abrasion materials and parameters. This review arrives at a few conclusions on the effectiveness of a material and parameter set, and that there is potential for developments in the area of standardizing parameter selection; also, there is scope for further studies on Bio-Active Glass as an alternative to the materials currently used in Air-Abrasion., Competing Interests: None, (Copyright: © Journal of Biomedical Physics and Engineering.)

Objectives: The geometry of carotid bifurcation is a crucial contributing factor to the localization of atherosclerotic lesions. Currently, studies on carotid bifurcation geometry are limited to the region near to bifurcation. This study aimed to determine the influence of carotid bifurcation geometry on the blood flow using numerical simulations considering magnitude of haemodynamic parameters in the extended regions of carotid artery., Methods: In the present study, haemodynamic analysis is carried out using the non-Newtonian viscosity model for patient-specific geometries consisting of both Left and Right carotid arteries. A 3D patient-specific geometric model is generated using MIMICS, and a numerical model is created using ANSYS., Results: The results obtained from patient-specific cases are compared. The influence of geometric features such as lumen diameter, bifurcation angle, and tortuosity on the haemodynamics parameters such as velocity, WSS, pressure, Oscillatory Shear Index (OSI), and Time-Averaged Wall Shear Stress (TAWSS) are compared., Conclusion: The results demonstrate significant changes in the flow regime due to the geometric shape of the carotid artery. It is observed that the lower value of TAWSS occurs near the bifurcation region and carotid bulb region. In addition, the higher value of the (OSI) is observed in the Internal Carotid Artery (ICA) and the tortuous carotid artery region. However, it is also observed that apart from the bifurcation angle, other factors, such as tortuosity and area ratio, play a significant role in the flow dynamics of the carotid artery., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier B.V.)

Ureters are essential components of the urinary system and play a crucial role in the transportation of urine from the kidneys to the bladder. In the current study, a three-dimensional ureter is modelled. A series of peristaltic waves are made to travel on the ureter wall to analyse and measure parameter effects such as pressure, velocity, gradient pressure, and wall shear at different time steps. The flow dynamics in the ureters are thoroughly analysed using the commercially available ANSYS-CFX software. The maximum pressure is found in the triple wave at the ureteropelvic junction and maximum velocity is observed in the single and double wave motion due to the contraction produced by the peristalsis motion. The pressure gradient is maximum at the inlet of the ureter during the single bolus motion. The contraction produces a high jet of velocity due to neck formation and also helps in urine trapping in the form of a bolus, which leads to the formation of reverse flow. Due to the reduction in area, shear stress builds on the ureter wall. The high shear stress may rupture the junctions in the ureter., (Creative Commons Attribution license.)

Objective: The nasal cavity effectively captures the particles present in inhaled air, thereby preventing harmful and toxic pollutants from reaching the lungs. This filtering ability of the nasal cavity can be effectively utilized for targeted nasal drug delivery applications. This study aims to understand the particle deposition patterns in three age groups: neonate, infant, and adult. Materials and methods: The CT scans are built using MIMICS 21.0, followed by CATIA V6 to generate a patient-specific airway model. Fluid flow is simulated using ANSYS FLUENT 2021 R2. Spherical monodisperse microparticles ranging from 2 to 60 µm and a density of 1100 kg/m 3 are simulated at steady-state and sedentary inspiration conditions. Results: The highest nasal valve depositions for the neonate are 25% for 20 µm, for infants, 10% for 50 µm, 15% for adults, and 15% for 15 µm. At mid nasal region, deposition of 15% for 20 µm is observed for infant and 8% for neonate and adult nasal cavities at a particle size of 10 and 20 µm, respectively. The highest particle deposition at the olfactory region is about 2.7% for the adult nasal cavity for 20 µm, and it is <1% for neonate and infant nasal cavities. Discussion and conclusions: The study of preferred nasal depositions during natural sedentary breathing conditions is utilized to determine the size that allows medication particles to be targeted to specific nose regions.

Patient-specific dynamic loadings are seldom considered during the evaluation of hip implants. The primary objective of this study is to check for the feasibility of the use of UHMWPE as the material for an acetabular cup o CoCr Alloy that is reported to produce a squeaking sound after replacement. An elliptical shaped stem with three different cross-sectional profiles is considered for simulation. Using a commercial finite element method, patient-specific dynamic forces were applied for the quantitative analysis. The loading and boundary conditions are used as per ISO and ASTM standards. The walking gait cycle is used with two widely used biocompatible materials: titanium and cobalt-chromium. Initially, only the stem is considered for the analysis to finalize the best out of the three profiles, along with the better material for the stem. Later the complete implant is used for the analysis. Profile 1 exhibits 1.25 and 1.17 times greater stress than Profile 2 for CoCr Alloy and Ti-6Al-4V, respectively. Similarly, Profile 3 displays stresses 1.26 and 1.25 times greater than Profile 2 for CoCr Alloy and Ti-6Al-4V, respectively. Comparatively, displacement in stem Profile 2 is 1.75 times higher in Ti-6Al-4V than CoCr Alloy. The full implant displacement at 14% gait cycle is 1.15% higher for the CoCr-acetabular column material combination when compared to UHMWPE. It can be concluded that UHMWPE can be used as the acetabular cup material instead of CoCr for the Profile 2 elliptical shaped hip implant to prevent squeaking after replacement., (© 2023 IOP Publishing Ltd.)

The transmission mechanism of artificial flapping-wing drones generally needs low weight and the fewest interconnecting components, making their development challenging. The four-bar Linkage mechanism for flapping actuation has generally been used till now with complex and heavy connecting designs, but our proposed novel perpendicularly organized 3-cylindrical joint mechanism is designed to be unique and lighter weight with smooth functioning performance. The proposed prototype transforms the rotary motion of the motor into a specific angle of flapping movement, where the dimensions and specifications of the design components are proportional to the obtained flapping angle. Power consumption and flapping actuation can be monitored by adjusting the motor's rotational speed to control the individual wing in this mechanism. The proposed mechanism consists of a crank with three slightly slidable cylindrical joints perpendicularly arranged to each other with a specified distance in a well-organized pattern to produce a flapping movement at the other end. In order to examine the kinematic attributes, a mathematical process approach is formulated, and kinematic simulations are performed using SIMSCAPE multibody MATLAB, PYTHON programming and COMPMECH GIM software. The proposed invention's real-time test bench prototype model is designed, tested and analyzed for flapping validation.

Insect RoboFlyers are interesting and active focuses of study but producing high-quality flapping robots that replicate insect flight is challenging., due to the dual requirement of both a sophisticated transmission mechanism with light weight and minimal intervening connections. This innovative mechanism was created to address the need for a producible structure that is small in size, small in mass, and has reduced design linkages. The proposed Single Crank-Slotted Dual Lever (SC-SDL) mechanism transforms rotational motion into specific angular motion at different velocities for each of its two strokes, i.e., the forward stroke and the return stroke. The discovery of a lag between the left and right lever motions in our design mechanism-I leads us to the conclusion that the flapping is asymmetric. To eliminate the position lag, the design has been altered, and a new design mechanism-II has been developed. Comparative kinematic analysis of both design systems is performed using simulations. Two-dimensional analysis of the base ornithopter configuration using ANSYS FLUENT yielded deeper insights regarding the influence of varying flapping frequency on critical flow metrics regarding adequate lift and thrust. For a flapping frequency of 24 Hz, adequate lift generation was achieved with minimal flow disturbances and wake interactions. Averaged dual wing estimations were made as part of the CFD study, which showed similar agreements. To validate the estimations, experimental tests were performed over the design mechanism-II configuration.

Endometriosis is a common benign and chronic inflammatory gynaecological disease due to functional endometrial glands and stroma in an ectopic location outside the uterine cavity. It affects 5-10% of reproductive age group women in the peak age of 24-29 years. However, women with infertility and chronic pelvic pain have an even greater prevalence, accounting for 30-50% and 90% of cases, respectively. Although it is a common entity, patients often get a delayed diagnosis because it is often subtle (hidden), missed, or confused with mimics, leading to misdiagnosis, which significantly affects patients' quality of life because they live in constant pain from undiagnosed endometriosis. Laparoscopy followed by histopathological confirmation is the gold standard for diagnosis, but it is an invasive procedure. MRI is an excellent non-invasive modality that helps in non-invasive diagnosis, with excellent delineation of the disease extent, and thus provides a presurgical mapping of the disease, which is helpful for the operating surgeon. Radiologists should be aware of all possible spectrum and diagnose this early and provide a detailed structured report mapping the entire extent of the disease process, which helps in effective treatment planning and successful outcomes in improving patients' quality of life., Competing Interests: The authors report no conflict of interest., (© Pol J Radiol 2022.)

Cerebral intracranial aneurysms are serious problems that can lead to stroke, coma, and even death. The effect of blood flow on cerebral aneurysms and their relationship with rupture are unknown. In addition, postural changes and their relevance to haemodynamics of blood flow are difficult to measure in vivo using clinical imaging alone. Computational simulations investigating the detailed haemodynamics in cerebral aneurysms have been developed in recent times not only to understand the progression and rupture but also for clinical evaluation and treatment. In the present study, the haemodynamics of a patient-specific case of a large aneurysm on the left side internal carotid bifurcation (LICA) and no aneurysm on the right side internal carotid bifurcation (RICA) was investigated. The simulation of these patient-specific models using fluid-structure interaction provides a valuable comparison of flow behavior between normal and aneurysm models. The influences of postural changes were investigated during standing, sleeping, and head-down (HD) position. Significant changes in flow were observed during the HD position and quit high arterial blood pressure in the internal carotid artery (ICA) aneurysm model was established when compared to the normal ICA model. The velocity increased abruptly during the HD position by more than four times (LICA and RICA) and wall shear stress by four times (LICA) to ten times (RICA). The complex spiral flow and higher pressures prevailing within the dome increase the risk of aneurysm rupture., (© 2022. The Author(s).)

Background and Objective: Neonates are preferential nasal breathers up to 3 months of age. The nasal anatomy in neonates and infants is at developing stages whereas the adult nasal cavities are fully grown which implies that the study of airflow dynamics in the neonates and infants are significant. In the present study, the nasal airways of the neonate, infant and adult are anatomically compared and their airflow patterns are investigated., Methods: Computational Fluid Dynamics (CFD) approach is used to simulate the airflow in a neonate, an infant and an adult in sedentary breathing conditions. The healthy CT scans are segmented using MIMICS 21.0 (Materialise, Ann arbor, MI). The patient-specific 3D airway models are analyzed for low Reynolds number flow using ANSYS FLUENT 2020 R2. The applicability of the Grid Convergence Index (GCI) for polyhedral mesh adopted in this work is also verified., Results: This study shows that the inferior meatus of neonates accounted for only 15% of the total airflow. This was in contrast to the infants and adults who experienced 49 and 31% of airflow at the inferior meatus region. Superior meatus experienced 25% of total flow which is more than normal for the neonate. The highest velocity of 1.8, 2.6 and 3.7 m/s was observed at the nasal valve region for neonates, infants and adults, respectively. The anterior portion of the nasal cavity experienced maximum wall shear stress with average values of 0.48, 0.25 and 0.58 Pa for the neonates, infants and adults., Conclusions: The neonates have an underdeveloped nasal cavity which significantly affects their airway distribution. The absence of inferior meatus in the neonates has limited the flow through the inferior regions and resulted in uneven flow distribution., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background and Objective: The bladder receives the urine from the kidney and ureter. The series of peristaltic waves facilitate urine transport to the bladder. The peristaltic flow in the ureter is associated with fluid trapping and material reflux, which may cause an increase in bladder pressure. It is difficult to visualize the complex peristalsis phenomenon, in the ureter using image and radiography experiments. A numerical simulation will help in the understanding of urine bolus formation and its effect on the ureter wall., Methods: A three-dimensional computational fluid dynamic analysis is carried out to understand the flow physics associated with bolus formation and the effect of reflux on the ureter. ANSYS-CFX, a commercially available computational dynamics package is used to simulate the peristalsis. A single sinusoidal peristaltic wave traveling along a circular tube will yield the velocity, pressure, wall shear stress distributions inside the ureter., Results: The propagation of the peristaltic wave results in the backflow of urine near the inlet at the beginning of the flow. As the wave propagates towards the outlet, the flow rate decreases. It is observed that pressure distribution along the ureter axis will deteriorate towards the outlet. The contraction produces a very high-pressure gradient which causes the urine backflow. The trapping and the bolus formation cause a significant rise in bolus pressure, simultaneously developing negative pressure at the contraction neck., Conclusions: The effect of peristalsis on the ureter biofluid dynamic behavior of the ureter is visualized in this study. It is established that the peristaltic contraction results in high-pressure formation at the bolus and negative pressure at the neck. It was found to be a maximum of 1.1 Pa at the bolus center and -1.13 Pa at the neck region. At the ureter pelvis junction, a higher wall shear of 0.095 Pa is observed as the wave starts to propagate. The velocity vectors show that the trapping of urine causes reflux and results in an adverse pressure gradient near the wall. A maximum pressure gradient of 485 Pa/meter was observed at the contraction of the ureter wall., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2021. Published by Elsevier B.V.)

Background and Objective: Total hip arthroplasty is known as one of the best advancements in orthopedics in the 20th century. Due to age or trauma hip joint has to replace by an artificial implant. After the hip arthroplasty, the patients can return to normal day-to-day activities with a normal range of motion. There are several types and designs are currently available. These designs usually depend upon the anatomy of the patients. There is a need for revision surgery due to dislocation and aseptic loosening in these joints over time in actively younger patients. Minor changes in the design stage can certainly improve the life expectancy of the implant and will also further reduce the revision rate., Methods: In this current work, finite element analysis is carried out by varying the neck length with a change in femoral head size for a circular-shaped stem. The effects of using a shorter neck are analyzed. A total of nine combinations are considered for analysis. Modeling is carried out in CATIA V-6 and analysis is performed in ANSYS R-19. A femoral head of 36, 40, and 44 mm and taper neck length of 18, 16, and 14 mm is considered. CoPE is considered as the material combination for all the models., Results: It was observed that the von Mises stresses in the complete implant tend to decrease with an increase in the femoral head size. Maximum 5% variation in stress values when 36 mm femoral head is compared with 44 mm. The stresses in the taper neck region tend to decrease with a decrease in the neck length. Minimum von Mises stress of 161.83 MPa was found for the complete implant and in the head-neck region, a minimum von Mises stress found 91.9 MPa., Conclusions: Performance evaluation of hip implant under static loading conditions gives a clear idea about the behavior of implant. It was found that a decrease in the von Mises stresses with a decrease in the taper length. However, these variations won't affect much in the performance of the hip implant. Also, a reduction in taper length can significantly increase the dislocation in the implant. So it is advised to consider the optimal taper length with an increase in the femoral head size., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2021. Published by Elsevier B.V.)

Guar gum (plant-based polysaccharide) is a promising candidate with immense potential. It is used as emulsifier, thickener, stabilizer, and as binding agent in many industries. In the present project, it was planned to synthesize guar gum based polyurethanes by varying the amount of guar gum. Guar gum (GG) was used along with hydroxyl-terminated polybutadiene (HTPB) as soft segment, which was then reacted with isophorone diisocyanate (IPDI) to form PU pre-polymers. In last step, these -NCO terminated pre-polymers were extended with 1,4 butane diol as chain extender. The prepared polyurethane samples were then characterized by using FTIR, solid-state 1 HNMR and X-ray diffraction (XRD). Thermal behavior of the samples was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Results indicated that the incorporation of guar gum in PU backbone improved its thermal behavior and crystallinity., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this study, we evaluated the morphological behavior of polyurethane elastomers (PUEs) by modifying the soft segment chain length. This was achieved by increasing the soft segment molecular weight ( Mn = 400-4000 gmol -1 ). In this regard, polycaprolactone diol (PCL) was selected as the soft segment, and 4,4'-cyclohexamethylene diisocyanate (H 12 MDI) and 1,6-hexanediol (HDO) were chosen as the hard segments. The films were prepared by curing polymer on Teflon surfaces. Fourier transform infrared spectroscopy (FTIR) was utilized for functional group identification in the prepared elastomers. FTIR peaks indicated the disappearance of -NCO and -OH groups and the formation of urethane (NHCOO) groups. The morphological behavior of the synthesized polymer samples was also elucidated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The AFM and SEM results indicated that the extent of microphase separation was enhanced by an increase in the molecular weight of PCL. The phase separation and degree of crystallinity of the soft and hard segments were described using X-ray diffraction (XRD). It was observed that the degree of crystallinity of the synthesized polymers increased with an increase in the soft segment's chain length. To evaluate hydrophilicity/hydrophobicity, the contact angle was measured. A gradual increase in the contact angle with distilled water and diiodomethane (38.6°-54.9°) test liquids was observed. Moreover, the decrease in surface energy (46.95-24.45 mN/m) was also found to be inconsistent by increasing the molecular weight of polyols.

Bionanocomposites is an emerging class of biohybrid materials, have a significant impact in environmental and biomedical fields owing to their high performance, lightweight, unique, and ecofriendly properties. A major challenge in the multiphase bionanocomposites system is to subtle control over the performance by managing the individual properties of reacting components. Herein, we presented the preliminary investigation on bionanocomposite system based on graphene nanoplatelets (GNPs) and hydroxyethyl cellulose graft poly(lactic acid) copolymer-polyurethane (HLAC-PU) with the aim to understand the structure property correlation for proposed applications in electronics and medical areas. The HLAC was fabricated by graft copolymerization of hydroxyethyl cellulose (HEC) and lactic acid (LA) with dibutyltin dilaurate. The HLAC was used to get a bio-functionalized PU matrix reinforced with GNPs by step-growth polymerization method. The structural, surface, and thermal properties of the HLAC and GNPs-HLAC-PU bionanocomposites were studied. The spectroscopic techniques confirmed the structure of bionanocomposites by the identification of related bands. The SEM/EDX results demonstrated that the 0.3 wt% of GNPs dispersed well in the HLAC-PU matrix and offered higher crystallinity. The reinforcement of the 0.3 wt% of GNPs has meaningfully enhanced the thermal stability producing higher residue contents. The reinforced GNPs filler increased the water resistance of bionanocomposites by reducing their water vapor permeability., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background and Objective: The hip joint is the vital joint that is responsible for the bodyweight transfer from the upper body to the lower body. Due to age these joints are worn out and need to be replaced by artificial hip implants. Wear is the predominant factor that is responsible for the loosening of hip implants. The wear occurs between the joints due to various reasons. The wear estimation at the design stage gives a clear idea about the life of the implants and also minor changes in the design may also significantly increase the life expectancy of the implant which can further reduce the rate of revision surgery. The linear wear rate is estimated in the taper trunnion surface., Methods: In this study, the circular and trapezoidal-shaped stem implant is designed, and wear studies are performed at the trunnion junction. The femoral head of size 28 mm, acetabular cup thickness of 4 mm, and a backing cup of thickness 2 mm are considered for the study. The neck taper radiuses at the top surface are altered. Ansys is used to perform the simulations., Results: At the time of assembly of the femoral head into the stem, the stresses were found to be increasing with an increase in the top surface radius of the neck taper junctions. However, when the walking conditions are considered for wear estimation of implants the circular implants with the 12/14 mm taper exhibited the lesser linear wear rate of 0.003 mm/year. The trapezoidal implants with the 10/14 mm taper exhibited a lesser linear wear rate of 0.032 mm/year., Conclusions: Wear is an important parameter that leads to the revision of implants due to loosening. It is found that with the decrease in the taper radius at the top surface against the standard 12/14 mm taper there is no significant decrease in the wear rate at the taper junction. Overall the circular implants exhibited less wear rate results over the trapezoidal-shaped stem implants. Due to the less linear wear rate, the circular implant has a higher life over the trapezoidal-shaped implant. Further, these implants can be manufactured to test using a hip simulator with the same conditions to validate the obtained results., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background and Objective: Finite element based simulation has emerged as a powerful tool to analyse the tooth strength and its fracture characteristics. The aim of this study is to compare and evaluate the fracture resistance of immature teeth reinforcement with MTA, Biodentine and Bioaggregate as an apical plug and backfill material using Finite Element Method., Methods: A 3D finite element analysis model was generated using a simulated immature maxillary central incisor. Seven different models were developed representing (Model 1): control group having an immature tooth model without any reinforcement material; (Model 2): Mineral trioxide aggregate (MTA) as apical plug 4 mm; (Model 3): Biodentine as apical plug 4 mm; (Model 4): Bioaggregate as apical plug 4 mm; (Model 5): MTA filled in the entire root canal 8.5 mm; (Model 6): Biodentine filled in the entire root canal 8.5 mm; (Model 7): Bioaggregate filled in the entire root canal 8.5 mm. A force of 100 N was applied at an angle of 130° to the palatal surface of the tooth. Stress distribution at cemento‑enamel junction was measured using the Von Mises stress criteria., Results: It was found that the 4 mm apical plug using MTA showed higher fracture resistance when compared to 8.5 mm backfill using MTA. When MTA was replaced as backfill material by Biodentine and Bioaggregate, the von mises stress increased by 64% and 94% respectively., Conclusions: It is not desirable to restore the entire root canal of an immature teeth using same material due to higher stress concentration at the cervical region. Considering the shorter setting time and improved handling characteristics, Biodentine can be preferred over the time‑tested MTA as an apical plug., Competing Interests: Declaration of Competing Interest The authors would like to state that there is no conflict of interest whatsoever for this manuscript., (Copyright © 2020 Elsevier B.V. All rights reserved.)

2-Hydroxyethyl cellulose graft polylactic acid copolymer (HLAC) was prepared by graft copolymerization of lactic acid (LA) and 2-hydroxyethyl cellulose (2-HEC), initiated by dibutyltin dilaurate (DBTDL) catalyst in aqueous media. Halloysite nanotubes (HNTs)/polyurethane (PU) bionanocomposites were prepared using the HLAC as chain extender in the step-growth polymerization. HNTs were dispersed in HLAC based PU matrix at different weight ratios of 0.30, 0.50, 1.00, and 3.00. Chemical structure and morphology of the graft copolymer and bionanocomposite elastomers were characterized using solid state 1 H NMR, ATR-FTIR, XRD, and SEM-EDX, while thermal degradation behavior was studied by TGA and DSC techniques. Surface morphology of the HNTs reinforced HLAC/PU bio-nanocomposites demonstrated the homogeneous dispersion of HNTs with little wavy rough surface at low contents which turned to be brittle at higher contents due to agglomerated HNTs. It is observed that the lower contents of HNTs were completely exfoliated in the HLAC/PU matrix. Crystalline pattern of the elastomers improved at lower contents of HNTs that enhanced the thermal stability of the bionanocomposites. The mechanical testing suggested that HNTs/HLAC/PU bionanocomposites have higher values of tensile strength and % elongation with only 0.3-0.5 wt% contents of HNTs that suggested the potential applications of elastomers at economic cost., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The present research project is planned to prepare novel biodegradable and biocompatible hydroxyethylcellulose-g-poly(lactic acid) (HEC-g-PLA) blended polyurethanes. Hydroxyl terminated polybutadiene (HTPB) was reacted with isophorone diisocyanate (IPDI) to produce NCO-terminated polyurethane prepolymer and extended further by varying the mole ratio of chain extenders (HEC-g-PLA and BDO). The synthesized polyurethane samples were characterized by using Fourier Transform Infrared (FTIR), proton solid-state NMR ( 1 H SS NMR) and X-ray diffraction (XRD). Thermal behavior of synthesized samples was checked by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Biological behavior of the synthesized PU samples was also tested by various biological activities which showed much dependence on the mole ratio of chain extenders. Results indicated that incorporation of grafted HEC in to the polyurethane backbone leads to improvement in antibacterial activity, anti-biofilm inhibition, biocompatibility and non-mutagenicity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study investigated the impact of paravalvular leakage (PVL) in relation to the different valve openings of the transcatheter aortic valve implantation (TAVI) valve using the fluid structure interaction (FSI) approach. Limited studies were found on the subject of FSI with regards to TAVI-PVL condition, which involves both fluid and structural responses in coupling interaction. Hence, further FSI simulation with the two-way coupling method is implemented to investigate the effects of hemodynamics blood flow along the patient-specific aorta model subjected to the interrelationship between PVL and the different valve openings using the established FSI software ANSYS 16.1. A 3D patient-specific aorta model is constructed using MIMICS software. The TAVI valve identical to Edward SAPIEN XT 26 (Edwards Lifesciences, Irvine, California), at different Geometrical Orifice Areas (GOAs), is implanted into the patient's aortic annulus. The leaflet opening of the TAVI valve is drawn according to severity of GOA opening represented in terms of 100%, 80%, 60%, and 40% opening, respectively. The result proved that the smallest percentage of GOA opening produced the highest possibility of PVL, increased the recirculatory flow proximally to the inner wall of the ascending aorta, and produced lower backflow velocity streamlines through the side area of PVL region. Overall, 40% GOA produced 89.17% increment of maximum velocity magnitude, 19.97% of pressure drop, 65.70% of maximum WSS magnitude, and a decrement of 33.62% total displacement magnitude with respect to the 100% GOA., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Adi A. Basri et al.)

The main aim of this research work was to incorporate modified hydroxyethylcellulose (HEC) into PDMS based polyurethanes. In the first part, modification of hydroxyethylcellulose was carried out by polymerizing lactic acid (LA) with HEC using ammonia water to prepare poly(lactic acid) grafted hydroxyethylcellulose (HEC-g-PLA). The maximum degree of grafting (59.5%) was achieved at: 1:9 mole ratio of HEC/LA, 2 h, 80 °C (for activation) and 4 h, 90 °C (for reaction) with 0.74 degree of substitution. In the second part, hydroxyl terminated polybutadiene (HTPB) was reacted with isophorone diisocyanate to produce NCO-terminated polyurethane prepolymer which in turn extended by chain extender to synthesize polydimethyl siloxane hydroxyl terminated (PDMS) based polyurethanes. Effect of incorporation of HEC-g-PLA as a chain extender was studied by varying its mole ratio in PDMS based PUs. Characterization of HEC-g-PLA and all PDMS/HEC-g-PLA based polyurethane samples was carried out by using Fourier Transform Infrared (FTIR) and proton solid-state NMR ( 1 H SS NMR). Biological behavior of synthesized samples was also tested by various biological activities and results indicated that incorporation of HEC-g-PLA in to PDMS based polyurethanes leads to improvement in antibacterial activity, anti-biofilm inhibition, biocompatibility and non-mutagenicity. Therefore, HEC-g-PLA/PDMS blended polyurethanes are promising biomaterials that have potential for various biomedical applications., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Natural products with therapeutic nature are nowadays warmly welcomed in textiles. Current study is concerned with isolation of tannin from neem bark ( Azadirachta indica ) and its application onto silk fabric. For improvement in shades, chemical & bio-mordants have been employed at optimal dyeing conditions. It is found that methanolic extract of pH 5 obtained 8 g dye powder after US Treatment for 30 min has given high color strength if used to dye irradiated silk for 65 min at 75 °C. Bio-mordanting using herbal plants has improved the color characteristics as compared to chemical mordants used. ISO standards for color fastness reveal that herbal based bio-mordants have improved the rating from good to excellent as compared to chemical mordants used. It is concluded that US treatment has not only isolate the colorant for neem bark under mild condition but also given excellent characteristic using bio mordants onto silk fabrics.

Background: The Hip joint is the primary joint which gives stability to the human body. The wear and tear associated with age and other factors, require these joints to be replaced by implants using hip arthroplasty surgeries. Cobalt chromium alloy (CoCr), titanium alloy, stainless steel are some of the most common hip joint materials used for hip implants. The design requirement for hip joint implants are very stringent to avoid revision joint surgeries due to aseptic loosening. There are various choices in shapes and materials used for stem and acetabular designs. This makes it more difficult to make an informed decision on the type of design and material that can be used for hip implants., Methods: Circular, Oval, ellipse and trapezoidal designs with three individual cross sections (defined as profile 1, profile 2 and profile 3) are considered for the study. All models are modeled using CATIA V-6. Static structural analysis is performed using ANSYS R-19 to arrive at the best possible design and material combination for stem and acetabular cup., Results: It was found that, profile 2 of all the four designs has the lowest possible deformation and von Mises stress when compared to profile 1 and profile 2. In general, profile 2 with trapezoidal stem has best outcomes in terms of its mechanical properties. Besides, stem designed with material CoCr and its associated acetabular cup with CoC (ceramic on ceramic) material can produce an implant having better properties and longer durability., Conclusions: CoCr was found to be the preferred choice of material for stem design. It was also observed that, irrespective of material considered for the analysis profile 2 with trapezoidal stem showcased lesser deformation and von Mises stress over the other eleven models. For analysis involving acetabular cups, CoC implants exhibited better mechanical properties over the conventional CoPE (Ceramic on polyethylene) materials such as Ultra-high molecular weight polyethylene (UHMWPE). It is inferred from the findings of this study that, the profile 2 with trapezoidal stem design made of CoCr material and acetabular cup made of CoC material is best suited for hip joint implants.

Development of curcumin-loaded mixed polymeric micelles based on chitosan, alginate, maltodextrin, pluronic F127, pluronic P123, and tween 80, by thin-film hydration method has been investigated in Bisphenol A induced diabetics rats. Curcumin (C 21 H 20 O 6 ) extracted from rhizomes of the "Curcuma longa" has attracted considerable attention of pharmaceutical researchers due to its low cost, excellent pharmacological activities and lesser side effects. Despite its diverse pharmacological properties, the therapeutic application of curcumin as an oral therapy has been limited due to its poor aqueous solubility, fixed chemical stability, and low bioavailability. In an attempt to overcome these limitations, we developed curcumin-loaded mixed polymeric micelles. Diabetes mellitus is a most common chronic carbohydrate metabolic disorder. The results clearly demonstrated the ability of developed formulation to reduce the elevated blood glucose level and lipid profile (total cholesterol, triglycerides). It maintained the body-weight, HDL cholesterol level, various biochemical parameters and accelerated the wound healing process when treated with these curcumin-based formulations. The treatment of curcumin loaded mixed polymeric formulations allowed a favorable inhibitory effect to these histopathological changes of liver, kidney, and pancreas. The newly developed curcumin-based formulations have proved superior therapeutic potential and excellent healing efficacy as compared to standard drugs and pure curcumin., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Chitosan has gained an increased interest of researchers due to its nontoxic, biodegradable, biocompatible and renewable properties as well as its antimicrobial activity. In this work, a series of chitosan-based waterborne polyurethane (CS-WPU) emulsions were synthesized. The synthesis was accomplished by using a two-step emulsion polymerization process. The pre-polymer was prepared using hexamethylene diisocyanate (HDI) and polyethylene glycol (PEG; MW = 6 kDa). Afterwards, the chain extension step was performed by using different mole ratios of chitosan. Moreover, the effect of chitosan on physicochemical properties of the emulsion was studied. To evaluate textile performances such as tear strength, tensile strength and pilling, the CS-WPU emulsion was applied on different plain weave polyester cotton dyed and printed fabrics by using pad-dry cure techniques. The antimicrobial activity of the treated and untreated fabrics was also evaluated via the agar diffusion method. The results displayed that incorporation of chitosan has prominent effects on tensile tear strength, tear strength and antimicrobial activity of polyester cotton dyed and printed fabrics. Moreover, antimicrobial activity was considerably enhanced as the mole ratio of the chitosan was increased. The results emphasize that CS-WPU based on HDI exhibits a better performance as compared to IPDI., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this work, chitin-curcumin based polyurethane elastomers (PUEs) were prepared by step growth polymerization technique using hydroxy terminated polybutadiene (HTPB), hexamethylene diisocyanate (HDI), chitin and curcumin. The molecular characterization was done by using FTIR and SS 1 HNMR techniques. The surface morphology and thermal stability was studied by scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA), respectively. Degree of absorption and swelling characters were also determined in water as well as in DMSO. The crystalline behavior of prepared elastomers was checked by using X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Results presented that crystallinity of elastomers increased by increasing the content of chitin due to formation of more ordered structure., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Our current research work comprised of synthesis of a series of novel chitosan based water dispersible polyurethanes. The synthesis was carried out in three steps, in first step, the NCO end capped PU-prepolymer was formed through the reaction between Polyethylene glycol (PEG) (Mn = 600), Dimethylolpropionic acid (DMPA) and Isophorone diisocyanate (IPDI). In second step, the neutralization step was carried out by using Triethylamine (TEA) which resulted the formation of neutralized NCO terminated PU-prepolymer, after that the last step chain extension was performed by the addition of chitosan and followed the formation of dispersion by adding calculated amount of water. The proposed structure of CS-WDPUs was confirmed by using FTIR technique. The antimicrobial activities of the plain weave poly-cotton printed and dyed textile swatches after application of CS-WDPUs were also evaluated. The results showed that the chitosan incorporation in to PU backbone has markedly enhanced the antibacterial activity of WDPUs. These synthesized CS-WDPUs are eco-friendly antimicrobial finishes (using natural bioactive agents such as chitosan) with potential applications on polyester/cotton textiles., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Gellan gum (GG), a linear negatively charged exopolysaccharide,is biodegradable and non-toxic in nature. It produces hard and translucent gel in the presence of metallic ions which is stable at low pH. However, GG has poor mechanical strength, poor stability in physiological conditions, high gelling temperature and small temperature window.Therefore,it is blended with different polymers such as agar, chitosan, cellulose, sodium alginate, starch, pectin, polyanaline, pullulan, polyvinyl chloride, and xanthan gum. In this article, a comprehensive overview of combination of GG with natural and synthetic polymers/compounds and their applications in biomedical field involving drug delivery system, insulin delivery, wound healing and gene therapy, is presented. It also describes the utilization of GG based materials in food and petroleum industry. All the technical scientific issues have been addressed; highlighting the recent advancement., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The present study describes a novel ecofriendly series of chitin/curcumin/1,4-butane diol (BDO) blend derived polyurethanes (PUs), using hydroxy terminated polybutadiene (HTPB) and hexamethylene diisocyanate (HDI) along with different mole ratio of chitin, curcumin and BDO. The structural and morphological elucidation of the prepared films was done by FTIR and SEM techniques. The swelling behavior of the films was analyzed in both water and DMSO, which showed that incorporation of chitin increases the hydrophobicity and decreases the rate of swelling. Thermal analysis of synthesized PU blends revealed better thermal stability with following mole ratio 1:0.5:0.5 of chitin: curcumin: BDO as determined by TGA and DSC techniques., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Pectins are natural complex heteropolysaccharides, composed of (1, 4)-linked α-d-galacturonic acid residues and variety of neutral sugars such as rhamnose, galactose and arabinose. It is second most abundant component of the cell wall of all land plants. It has wide applications in various fields due to its use as gelling, emulsifying or stabilizing agent and as well as its non-toxic, biocompatible and biodegradable nature. Considering these versatile properties this review sheds a light on the synthesis, modification, characterization and applications of pectin based polymers. Most of them are used in industries, pharmaceutics, nutraceutics, drug delivery, tissue engineering, food packaging and cosmetics. Properties of pectin can be improved and modified by forming derivatives, blends and composites., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Glycoproteins have multidimensional properties such as biodegradability, biocompatibility, non-toxicity, antimicrobial and adsorption properties; therefore, they have wide range of applications. They are blended with different polymers such as chitosan, carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polycaprolactone (PCL), heparin, polystyrene fluorescent nanoparticles (PS-NPs) and carboxyl pullulan (PC) to improve their properties like thermal stability, mechanical properties, resistance to pH, chemical stability and toughness. Considering the versatile charateristics of glycoprotein based polymers, this review sheds light on synthesis and characterization of blends and composites of glycoproteins, with natural and synthetic polymers and their potential applications in biomedical field such as drug delivery system, insulin delivery, antimicrobial wound dressing uses, targeting of cancer cells, development of anticancer vaccines, development of new biopolymers, glycoproteome research, food product and detection of dengue glycoproteins. All the technical scientific issues have been addressed; highlighting the recent advancement., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Carrageenan is a natural polysaccharide extracted from edible red seaweeds of Rhodophycea class. It has been used as a viscosity increasing or gelling agent for prolonged and controlled drug release, food, pharmaceuticals and other industries. However, in spite of wide range of applications, carrageenan has some drawbacks and adverse effects on the biological systems, so its modifications with natural and synthetic polymers are carried out. This review article presents different sources and properties of carrageenans with special emphasis on natural polymer based carrageenan blends and composites and their applications in controlled drug delivery system, wound dressing and tissue engineering because of their biodegradability and biocompatibility, food industry as thickening/gelling materials, cosmeceuticals and making polyelectrolyte complexes., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Exopolysaccharides are synthesized by bacteria and secreted into the external environment and they may be homopolymeric or heteropolymeric in configuration. They are believed to protect bacterial cells from heavy metals, desiccation or other environmental effect. EPS exhibit antitumor, anti-HIV, emulsion stabilization capacity, shear-thinning activity, suspension ability, high viscosities, excellent biocompatibility, high biodegradability and immunomodulatory properties. They are widely used in herbicides, functional food, nutraceuticals, cosmeceuticals, pharmaceuticals, insecticides, immunomodulation and anticoagulants. This review shed light on the properties and versatile applications of xanthan, curdlan, hyaluronic acid and dextran blends and composites with natural and synthetic polymers., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A series of aqueous dispersions of polyurethane (PU) and low molecular weight chitosan (CS (LMW) ) has been prepared in two steps synthetic process. In first step PU prepolymer, with NCO termini were prepared by reacting isophrone diisocyanate (IPDI), poly (caprolactone) diol (CAPA, Mn 1000), and 2,2-dimethylol propionic acid (DMPA), followed by neutralization of PU prepolymer with triethylamine (TEA). In second step PU prepolymer chain was extended by low molecular weight chitosan followed by dispersion formation by adding calculated volume of water. Molecular characterization of CS (LMW) -PU finishes was done by FTIR and application on poly-cotton blended fabric samples was confirmed by scanning electron microscopy (SEM). Antimicrobial and UV protective performance of treated fabrics was performed by AATCC 100 and AATCC TM183 methods respectively. Furthermore, it shows that the addition of chitosan remarkably increases antimicrobial and UV protective properties of PUs., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Lipids are the main source of energy and widely used for various applications. In this review, the modification of lipids by using them in combination with other biomaterials like natural and synthetic polymers is elaborated. These new blends have characteristic features of both polymers and are characterized by different techniques (NMR, DSC, TGA, IR and Raman spectroscopy etc.) to understand their structure, properties and functional behavior. Lipids are hydrophobic, have anti-oxidant and anti-bacterial properties and thus impart hydrophobicity and flexibility to the polymers. While the polymers, on the other hand, make the lipids tougher. Properties of few polymers such as starch, polyethylene protein and chitosan that have brittleness, low combustion rate and hydrophobicity, are improved by incorporation of lipids ultimately increased their flexibility, combustion rate and hydrophobicity respectively. This review article is also focused on emerging fields for the applications of these composite materials. The most notable application of composite materials are in the field of paint industry., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Lignin and lignin derivatives biopolymers have several properties, such as high thermal stability, antioxidant, biodegradability, antimicrobial actions, adhesive properties, etc., and thus they can be extensively used in wide range of areas. Although human history mostly depend on the biopolymers, however derivatives of lignin such as sulfonate, phenolic, organosolv, Kraft and sodium sulfonate lignin have good mechanical and physicochemical properties. Well-designed materials such as coatings and paints, manufacturing of plastics and resins, for rubber packaging, for fuel production etc., can be obtained by the functionalizations of chemically modified lignin. Considering multi purposes properties of the lignin and lignin derivatives and extensive industrial applications of derivatives, this review sheds a light on lignin derivatives based materials with their prospective applications. All the technical scientific issues have been addressed highlighting the recent advancement., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A series of polyurethane dispersions were synthesized through two step polymerization technique. A PU prepolymer with NCO termini was prepared using isophorone diisocyanate (IPDI), poly caprolactone diols (CAPA of mol. wt. 1000) and DMPA (3:1:1), and PU prepolymer chain was extended with different mole ratios of low molecular weight chitosan and finally aqueous emulsion was prepared by adding suitable volume of water. The proposed structure of chitosan based PU dispersions was confirmed through FTIR spectroscopy. The prepared aqueous CS (LMW) -CPUIs emulsions were applied onto the different quality plain weave poly-cotton dyed and printed fabric pieces using pad-dry-cure procedures. The physical properties such as air permeability, stiffness and crease recovery angle (CRA), pilling resistance, tear and tensile strength of the treated and untreated fabric samples were also evaluated. The results revealed that the incorporation of chitosan has pronounced effect on the properties of treated fabrics. This research could be extended in future for performance evaluation of pure cotton and woolen fabrics., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Bio-nanocomposites, composed of biopolymers and inorganic solids, show dimensions in the nanometer range (1-100nm) which can be widely used in variety of areas owing to multidimensional properties like biocompatibility, antimicrobial activity and biodegradability. Considering these versatile properties of the bio-nanocomposites this review sheds a light on the synthesis, modification, characterization and applications of bio-nanocomposites based on different polysaccharides functionalized by different nanofillers such as MMT, Ag, SiO 2, TiO 2, and ZnO. Most of them have been used in regenerative medicine, drug delivery, tissue engineering, electronics and food packaging. The modification of clays with biopolymers results an attractive alternative in the development of environmentally friendly materials for pollutants removal. All the technical scientific issues have been addressed highlighting the recent advancement., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this work, new hexamethylene diisocyanate (HMDI) and hyroxylterminated polybutadiene (HTPB) based polyurethanes (PUs) were prepared following step growth polymerization by the introduction of varying mole ratio of chitosan (CH) and curcumin (CUR). Structural study of blends through infrared spectroscopy confirmed the incorporation of CH and CUR into the backbone of the PU. The scanning electron microscopic (SEM) study confirmed the well dispersion of incorporated chitosan/curcumin and homogeneity of surface of synthesized samples. Thermogravimetric analysis (TGA) of PU blends indicated a better thermal stability with 0.25M:0.75M of chitosan to curcumin. Mechanical properties such as modulus and tensile strength of PU blends were found to be better with higher contents of chitosan and curcumin. The same extender composition (1mol BDO, 075mol chitosan and 0.25mol curcumin) based PU showed higher substantial of antimicrobial activity as compared to the all other PUs. On the whole, this work is actually a step towards the generation of novel biocompatible materials preferably useful for biomedical applications., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Traditional mineral oil based plastics are important commodity to enhance the comfort and quality of life but the accumulation of these plastics in the environment has become a major universal problem due to their low biodegradation. Solution to the plastic waste management includes incineration, recycling and landfill disposal methods. These processes are very time consuming and expensive. Biopolymers are important alternatives to the petroleum-based plastics due to environment friendly manufacturing processes, biodegradability and biocompatibility. Therefore use of novel biopolymers, such as polylactide, polysaccharides, aliphatic polyesters and polyhydroxyalkanoates is of interest. PHAs are biodegradable polyesters of hydroxyalkanoates (HA) produced from renewable resources by using microorganisms as intracellular carbon and energy storage compounds. Even though PHAs are promising candidate for biodegradable polymers, however, the production cost limit their application on an industrial scale. This article provides an overview of various substrates, microorganisms for the economical production of PHAs and its copolymers. Recent advances in PHAs to reduce the cost and to improve the performance of PHAs have also been discussed., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Polysaccharides derived from plants are one of the largest groups of natural compounds that offer potentially beneficial functions and properties. Glucomannan, a bioactive polymer belonged to mannan family of polysaccharides is fairly abundant in nature along with superior gelling and film forming properties. Glucomannan and its derivative with several synthetic polymers are used in a biomedical and food sector especially. Polyurethanes (PUs), a commercially useful class of polymers are extensively used in both industry and everyday life because they retain exceptional properties of both plastics and elastomers. This review addresses the properties and applications of glucomannan based materials with the aim to be explored this less attempted polymer further. Furthermore this paper also presents an overview of current status and perspectives of glucomannan based polyurethane materials., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Chitin and chitosan are amino polysaccharides having multidimensional properties, such as biocompatibility, biodegradability, antibacterial properties and non-toxicity, muco-adhesivity, adsorption properties, etc., and thus they can be widely used in variety of areas. Although human history mainly relies on the biopolymers, however synthetic materials like polyvinyl alcohol (PVA) have good mechanical, chemical and physical properties. Functionalization of PVA with chitin and chitosan is considered very appropriate for the development of well-designed biomaterials such as biodegradable films, for membrane separation, for tissue engineering, for food packaging, for wound healing and dressing, hydro gels formation, gels formation, etc. Considering versatile properties of the chitin and chitosan, and wide industrial and biomedical applications of PVA, this review sheds a light on chitin and chitosan based PVA materials with their potential applications especially focusing the bio-medical field. All the technical scientific issues have been addressed highlighting the recent advancement., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Algal biomass is an excellent renewable resource for the production of polymers and other products due to their higher growth rate, high photosynthetic efficiency, great potential for carbon dioxide fixation, low percentage of lignin and high amount of carbohydrates. Algae contain unique metabolites which are transformed into monomers suitable for development of novel polyesters. This review article mainly focuses on algal bio-refinery concept for polyester synthesis and on exploitation of algae-based biodegradable polyester blends and composites in tissue engineering and controlled drug delivery system. Algae-derived hybrid polyester scaffolds are extensively used for bone, cartilage, cardiac and nerve tissue regeneration due to their biocompatibility and tunable biodegradability. Microcapsules and microspheres of algae-derived polyesters have been used for controlled and continuous release of several pharmaceutical agents and macromolecules to produce humoral and cellular immunity with efficient intracellular delivery., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Chitin and chitosan are amino polysaccharides having massive structural propensities to produce bioactive materials with innovative properties, functions and diverse applications particularly in biomedical field. The specific physico-chemical, mechanical, biological and degradation properties offer efficient way to blend these biopolymers with synthetic ones. Polyurethane (PU) gained substantial attention owing to its structure-properties relationship. The immense activities of chitin/chitosan are successfully utilized to enhance the bioactive properties of polyurethanes. This review shed a light on chitin and chitosan based PU materials with their potential applications especially focusing the bio-medical field. All the technical scientific issues have been addressed highlighting the recent advancement in the biomedical field., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Polyurethanes (PUs) are considered currently as one of the established bio compatible and blood compatible biomaterials offering tremendous structure-property relationship. But few limitations such as low resistance to micro-emboli and thrombi are still associated with these biomaterials that restricted their applications and hence need to be modified. Heparin, a highly sulfonated and negatively charged member of glycosaminoglycan family is well established for their anti-thrombin, anticoagulant and many biological activities that make it a highly attractive candidate capable of modifying or tailoring polymer properties. Incorporation of heparin for the improvement of biocompatibility of PUs is an interesting approach and enabling emerging technology. This review focuses on the methods used for modification of PUs via heparin with their pros and cons. The major PU-heparin systems with the recent developments and their possible biomedical applications are discussed., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A significantly growing interest is to design a new strategy for development of bio-polyesters from renewable resources due to limited fossil fuel reserves, rise of petrochemicals price and emission of green house gasses. Therefore, this review aims to present an overview on synthesis of biocompatible, biodegradable and cost effective polyesters from biomass and their prospective in different fields including packaging, coating, tissue engineering, drug delivery system and many more. Isosorbide, 2,4:3,5-di-O-methylene-d-mannitol, bicyclic diacetalyzed galactaric acid, 2,5-furandicarboxylic acid, citric, 2,3-O-methylene l-threitol, dimethyl 2,3-O-methylene l-threarate, betulin, dihydrocarvone, decalactone, pimaric acid, ricinoleic acid and sebacic acid, are some important monomers derived from biomass which are used for bio-based polyester manufacturing, consequently, replacing the petrochemical based polyesters. The last part of this review highlights some recent advances in polyester blends and composites in order to improve their properties for exceptional biomedical applications i.e. skin tissue engineering, guided bone regeneration, bone healing process, wound healing and wound acceleration., (Copyright © 2015 Elsevier B.V. All rights reserved.)