Advances in design of polymer brush functionalized inorganic nanomaterials and their applications in biomedical arena.

Grafting of polymer brush (assembly of polymer chains tethered to the substrate by one end) is emerging as one of the most viable approach to alter the surface of inorganic nanomaterials. Inorganic nanomaterials despite their intrinsic functional superiority, their applications remain restricted due to their incompatibility with organic or biological moieties vis-à-vis agglomeration issues. To overcome such a shortcoming, polymer brush modified surfaces of inorganic nanomaterials have lately proved to be of immense potential. For example, polymer brush-modified inorganic nanomaterials can act as efficient substrates/platforms in biomedical applications, ranging from drug-delivery to protein-array due to their integrated advantages such as amphiphilicity, stimuli responsiveness, enhanced biocompatibility, and so on. In this review, the current state of the art related to polymer brush-modified inorganic nanomaterials focusing, not only, on their synthetic strategies and applications in biomedical field but also the architectural influence of polymer brushes on the responsiveness properties of modified nanomaterials have comprehensively been discussed and its associated future perspective is also presented. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Facile one-pot in-situ synthesis of novel graphene oxide-cellulose nanocomposite for enhanced azo dye adsorption at optimized conditions.

This is the first report on utilization of modified Hummers' method for in-situ synthesis of novel graphene oxide-cellulose nanocrystals nanocomposite in a single reaction vessel. Cellulose used for nanocomposite preparation was extracted from waste jute. The synthesized nanocomposite was characterized with FTIR, XRD, SEM, EDX, DLS, and Zeta potential analyzer. It was applied as an adsorbent for the removal of toxic dye methylene blue from aqueous solutions. Around 98 % MB removal was achieved in 135 min. Under optimum experimental conditions recommended by response surface methodology, adsorption capacity of the nanocomposite was found to be 334.19 mg g-1 while the maximum adsorption capacity as determined by Langmuir isotherm 751.88 mg g-1. Further analysis revealed that the process was guided by both Langmuir and Freundlich isotherm and followed pseudo-second-order kinetics. This cost-effective synthesis route and efficient adsorption capacity of the nanocomposite indicate its immense potential for large-scale application in wastewater treatment.

Sustained release of ketorolac tromethamine from poloxamer 407/cellulose nanofibrils graft nanocollagen based ophthalmic formulations.

There has been extensive utilization of poloxamer 407 (PM) for the delivery of various ophthalmic drugs aimed at efficient ophthalmic drug delivery approach for longer precorneal residence time along with acceptable bioavailability of drugs. We have studied the effect of nanocellulose grafted collagen (CGC) on the performance of in situ gels based on PM for the controlled in vitro release of Ketorolac Tromethamine (KT). CGC has shown great influence evident by the reduction in PM critical gelation concentration, increased gel strength, and prolonged the release of loaded drugs compared with the virgin PM gel. The engineered nanocomposite formulations established an anomalous diffusion mechanism along with a Fickian diffusion controlled drug release for 1.5 & 1.75 w/v% CGC reinforced PM. Hence, the synthesized in situ nanocomposites are potential candidates for ophthalmic drug delivery system.

Evaluation of Magnesium as an adjuvant in Ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded randomized controlled study.

OBJECTIVE: Different additives have been used to prolong brachial plexus block. We evaluated the effect of adding magnesium sulfate to ropivacaine for supraclavicular brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia. METHODS: One hundred patients (25-55 years) posted for elective forearm and hand surgeries under supraclavicular brachial plexus block were divided into two equal groups (Groups RM and RN) in a randomized, double-blind fashion. In group RM (n = 50), 30 ml 0.5% ropivacaine plus 150 mg (in 1 ml 0.9% saline) magnesium sulfate and in group RN (n = 50), 30 ml 0.5% ropivacaine plus 1 ml normal saline were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamic variables, and side effects were recorded for each patient. FINDINGS: Though with similar demographic profile and block (sensory and motor) onset time, the sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RM (P = 0.026) than group RN. Postoperative VAS values at 24 h were significantly lower in group RM (P = 0.045). Intraoperative hemodynamics was comparable among two groups and no appreciable side effect was noted throughout the study period. CONCLUSION: It can be concluded from this study that adding magnesium sulfate to supraclavicular brachial plexus block may increase the sensory and motor block duration and time to first analgesic use, and decrease total analgesic needs, with no side effects.

Pain relief in day care arthroscopic knee surgery: A comparison between intra-articular ropivacaine and levobupivacaine: A prospective, double-blinded, randomized controlled study.

BACKGROUND: Post-operative pain frequently hampers implementation of day care arthroscopic knee surgery in spite of so many analgesic, local anesthetic drugs and routes of administration. AIMS: The aim of the present study was carried out to compare the efficacy of ropivacaine and levobupivacaine when administered through intra-articular route in controlling pain after day care arthroscopic knee surgery. SETTING AND DESIGN: It was a prospective, double-blinded and randomized controlled study. MATERIALS AND METHODS: April 2008-December 2008, 60 patients of both sex, of American Society of Anesthesiologists physical status I and II, undergoing day care arthroscopic knee surgery were randomly assigned into two groups (R, L). Group R received 10 ml of 0.75% ropivacaine, whereas group L received 10 ml of 0.50% levobupivacaine through intra-articular route at the end of the procedure. Pain assessed using visual analog scale (VAS) and diclofenac sodium given as rescue analgesia when VAS >3. Time of first analgesic request and total rescue analgesic were calculated. STATISTICAL ANALYSIS AND RESULTS: based on comparable demographic profiles; time for the requirement of first post-operative rescue analgesia (242.16 ± 23.86 vs. 366.62 ± 24.42) min and total mean rescue analgesic requirement was (104.35 ± 18.96 vs. 76.82 ± 14.28) mg in group R and L respectively. Group R had higher mean VAS score throughout the study period. No side effects found among the groups. These two results were clinically and statistically significant (P < 0.05). CONCLUSION: Hence, it was evident that intra-articular levobupivacaine give better post-operative pain relief, with an increase in time of first analgesic request and decreased need of total post-operative analgesia compared with ropivacaine.

PONV in Ambulatory surgery: A comparison between Ramosetron and Ondansetron: a prospective, double-blinded, and randomized controlled study.

BACKGROUND: postoperative nausea and vomiting (PONV) frequently hampers implementation of ambulatory surgery in spite of so many antiemetic drugs and regimens. AIMS: the study was carried out to compare the efficacy of Ramosetron and Ondansetron in preventing PONV after ambulatory surgery. SETTING AND DESIGN: it was a prospective, double blinded, and randomized controlled study. METHODS: 124 adult patients of either sex, aged 25-55, of ASA physical status I and II, scheduled for day care surgery, were randomly allocated into Group A [(n=62) receiving (IV) Ondansetron (4 mg)] and Group B [(n=62) receiving IV Ramosetron (0.3 mg)] prior to the induction of general anesthesia in a double-blind manner. Episodes of PONV were noted at 0.5, 1, 2, 4 h, 6, 12, and 18 h postoperatively. STATISTICAL ANALYSIS AND RESULTS: statistically significant difference between Groups A and B (P <0.05) was found showing that Ramosetron was superior to Ondansetron as antiemetic both regarding frequency and severity. CONCLUSION: it was evident that preoperative prophylactic administration of single dose IV Ramosetron (0.3 mg) has better efficacy than single dose IV Ondansetron (4 mg) in reducing the episodes of PONV over 18 h postoperatively in patients undergoing day-care surgery under general anesthesia.

Pain relief after Arthroscopic Knee Surgery: A comparison of intra-articular ropivacaine, fentanyl, and dexmedetomidine: A prospective, double-blinded, randomized controlled study.

BACKGROUND: Postoperative pain is very common distressing symptom after any surgical procedure. Different drugs in different routes have been used for controlling post-arthroscopic pain. No one proved to be ideal. We have compared the analgesic effect of ropivacaine, fentanyl, and dexmedetomidine when administered through the intra-articular route in arthroscopic knee surgery. MATERIALS AND METHODS: From March 2008 to July 2010, 99 patients undergoing arthroscopic knee surgery were randomly assigned into three groups (A,B,C) in a prospective double-blinded fashion. Group A received 10 ml of 0.75% ropivacaine, where Group B received 50 µg fentanyl, and Group C received 100 µg of dexmedetomidine through the intra-articular route at the end of procedure. Pain assessed using visual analog scale and diclofenac sodium given as rescue analgesia when VAS >4. Time of first analgesia request and total rescue analgesic used in 24 hours were calculated. RESULTS: Demographic profiles are quite comparable among the groups. Time for requirement of first postoperative rescue analgesia in Group A was 380.61 ± 22.973 min, in Group B was 326.82 ± 17.131 min and in Group C was 244.09 ± 20.096 minutes. Total rescue analgesia requirement was less in Group A (1.394 ± 0.496) compared to Group B (1.758 ± 0.435) and Group C (2.546 ± 0.546). Group A had higher mean VAS score at 6(th) and 24(th) postoperative hours. No side effects found among the groups. CONCLUSION: Therefore, it suggests that intra-articular ropivacaine gives better postoperative pain relief, with increased time of first analgesic request and decreased need of total postoperative analgesia compared to fentanyl and dexmedetomidine.

Epidemiology of cervical spinal cord injury in eastern India: an autopsy-based study.

AIMS: Cervical spinal cord injury is a major cause of fatality among trauma victims. Unlike developed countries, national spinal cord injury database is not maintained in India. Paucity of data hampers the understanding of epidemiology of the event in India. So, this study was conducted to ascertain the epidemiological pattern of death due to cervical spinal cord injury and to identify the risk factors; also to find the association of vertebral injuries with various epidemiological parameters. METHODS: Among autopsies conducted in Burdwan Medical College and Hospital from 2000 to 2010, cases with autopsy report mentioning "death due to cervical spinal cord injury" either primary or secondary were included in the study. It was a retrospective observational study based on autopsy report. RESULTS: 536 cases met the inclusion criteria. Among them 89.4% were male and 10.6% were female; 63.8% victims were young adults (20-39 years). Mean (plus or minus S.D.) age was 33.5 years (plus or minus 12.8). All, apart from 5.4%, suffered from single segment injury with commonest site being C3-C4 (37.3%). Highest number of trauma occurred between 6 am to 9 am, 56.6% of the victims died before hospitalisation. Commonest mode of injury was road traffic accident (52.2%) followed by fall from height (25.0%); 53.7% cases had vertebral fracture with dislocation, 34.3% had only vertebral fracture. Only dislocation was significantly high up to 19 years age (p<0.001) and among females (p=0.029). All elderly suffered from fracture. CONCLUSIONS: This study revealed an unusually high male:female ratio with much representation of the younger age groups in the injuries in comparison to other parts of world. In absence of national database, this result can be used as a surrogate data.