24 research outputs found
Electrosprayed mesoporous particles for improved aqueous solubility of a poorly water soluble anticancer agent: in vitro and ex vivo evaluation
open access articleEncapsulation of poorly water-soluble drugs into mesoporous materials (e.g. silica) has evolved as a favorable
strategy to improve drug solubility and bioavailability. Several techniques (e.g. spray drying, solvent evaporation,
microwave irradiation) have been utilized for the encapsulation of active pharmaceutical ingredients (APIs) into
inorganic porous matrices. In the present work, a novel chalcone (KAZ3) with anticancer properties was successfully
synthesized by Claisen-Schmidt condensation. KAZ3 was loaded into mesoporous (SBA-15 and MCM-41)
and non-porous (fumed silica, FS) materials via two techniques; electrohydrodynamic atomization (EHDA) and
solvent impregnation. The effect of both loading methods on the physicochemical properties of the particles (e.g.
size, charge, entrapment efficiency, crystallinity, dissolution and permeability) was investigated. Results indicated
that EHDA technique can load the active in a complete amorphous form within the pores of the silica particles.
In contrast, reduced crystallinity (~79%) was obtained for the solvent impregnated formulations. EHDA
engineered formulations significantly improved drug dissolution up to 30-fold, compared to the crystalline drug.
Ex vivo studies showed EHDA formulations to exhibit higher permeability across rat intestine than their solvent
impregnated counterparts. Cytocompatibility studies on Caco-2 cells demonstrated moderate toxicity at high concentrations
of the anticancer agent. The findings of the present study clearly show the immense potential of
EHDA as a loading technique for mesoporous materials to produce poorly water-soluble API carriers of high payload
at ambient conditions. Furthermore, the scale up potential in EHDA technologies indicate a viable route to
enhance drug encapsulation and dissolution rate of loaded porous inorganic materials
The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom
Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH
Outcomes following surgery in subgroups of comatose and very elderly patients with chronic subdural hematoma
Increasing age and lower pre-operative Glasgow coma score (GCS) are associated with worse outcome after surgery for chronic subdural haematoma (CSDH). Only few studies have quantified outcomes specific to the very elderly or comatose patients. We aim to examine surgical outcomes in these patient groups. We analysed data from a prospective multicentre cohort study, assessing the risk of recurrence, death, and unfavourable functional outcome of very elderly (≥ 90 years) patients and comatose (pre-operative GCS ≤ 8) patients following surgical treatment of CSDH. Seven hundred eighty-five patients were included in the study. Thirty-two (4.1%) patients had pre-operative GCS ≤ 8 and 70 (8.9%) patients were aged ≥ 90 years. A higher proportion of comatose patients had an unfavourable functional outcome (38.7 vs 21.7%; p = 0.03), although similar proportion of comatose (64.5%) and non-comatose patients (61.8%) functionally improved after surgery (p = 0.96). Compared to patients aged < 90 years, a higher proportion of patients aged ≥ 90 years had unfavourable functional outcome (41.2 vs 20.5%; p < 0.01), although approximately half had functional improvement following surgery. Mortality risk was higher in both comatose (6.3 vs 1.9%; p = 0.05) and very elderly (8.8 vs 1.1%; p < 0.01) groups. There was a trend towards a higher recurrence risk in the comatose group (19.4 vs 9.5%; p = 0.07). Surgery can still provide considerable benefit to very elderly and comatose patients despite their higher risk of morbidity and mortality. Further research would be needed to better identify those most likely to benefit from surgery in these groups
The management and outcome for patients with chronic subdural hematoma: A prospective, multicenter, observational cohort study in the United Kingdom
OBJECTIVESymptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH.METHODSData on management and outcomes for patients with CSDH referred to UK and Ireland NSUs were collected prospectively over an 8-month period and audited against criteria predefined from the literature: NSU mortality < 5%, NSU morbidity < 10%, symptomatic recurrence within 60 days requiring repeat surgery < 20%, and unfavorable functional status (modified Rankin Scale score of 4–6) at NSU discharge < 30%.RESULTSData from 1205 patients in 26 NSUs were collected. Bur-hole craniostomy was the most common procedure (89%), and symptomatic recurrence requiring repeat surgery within 60 days was observed in 9% of patients. Criteria on mortality (2%), rate of recurrence (9%), and unfavorable functional outcome (22%) were met, but morbidity was greater than expected (14%). Multivariate analysis demonstrated that failure to insert a drain intraoperatively independently predicted recurrence and unfavorable functional outcome (p = 0.011 and p = 0.048, respectively). Increasing patient age (p < 0.00001), postoperative bed rest (p = 0.019), and use of a single bur hole (p = 0.020) independently predicted unfavorable functional outcomes, but prescription of high-flow oxygen or preoperative use of antiplatelet medications did not.CONCLUSIONSThis is the largest prospective CSDH study and helps establish national standards. It has confirmed in a real-world setting the effectiveness of placing a subdural drain. This study identified a number of modifiable prognostic factors but questions the necessity of some common aspects of CSDH management, such as enforced postoperative bed rest. Future studies should seek to establish how practitioners can optimize perioperative care of patients with CSDH to reduce morbidity as well as minimize CSDH recurrence. The BNTRC is unique worldwide, conducting multicenter trainee-led research and audits. This study demonstrates that collaborative research networks are powerful tools to interrogate clinical research questions.Society of British Neurological Surgeons. PJH supported by NIHR Research Professorship and NIHR Cambridge Biomedical Research Centre.This is the author accepted manuscript. It is permanently embargoed to comply with the publisher’s copyright terms. The final version is available via https://doi.org/10.3171/2016.8.JNS1613
Outcomes following surgery in subgroups of comatose and very elderly patients with chronic subdural hematoma
Increasing age and lower pre-operative Glasgow coma score (GCS) are associated with worse outcome after surgery for chronic subdural haematoma (CSDH). Only few studies have quantified outcomes specific to the very elderly or comatose patients. We aim to examine surgical outcomes in these patient groups. We analysed data from a prospective multicentre cohort study, assessing the risk of recurrence, death, and unfavourable functional outcome of very elderly (≥ 90 years) patients and comatose (pre-operative GCS ≤ 8) patients following surgical treatment of CSDH. Seven hundred eighty-five patients were included in the study. Thirty-two (4.1%) patients had pre-operative GCS ≤ 8 and 70 (8.9%) patients were aged ≥ 90 years. A higher proportion of comatose patients had an unfavourable functional outcome (38.7 vs 21.7%; p = 0.03), although similar proportion of comatose (64.5%) and non-comatose patients (61.8%) functionally improved after surgery (p = 0.96). Compared to patients aged < 90 years, a higher proportion of patients aged ≥ 90 years had unfavourable functional outcome (41.2 vs 20.5%; p < 0.01), although approximately half had functional improvement following surgery. Mortality risk was higher in both comatose (6.3 vs 1.9%; p = 0.05) and very elderly (8.8 vs 1.1%; p < 0.01) groups. There was a trend towards a higher recurrence risk in the comatose group (19.4 vs 9.5%; p = 0.07). Surgery can still provide considerable benefit to very elderly and comatose patients despite their higher risk of morbidity and mortality. Further research would be needed to better identify those most likely to benefit from surgery in these groups
Preparation and characterisation of bioadhesive microparticles comprised of low degree of quaternization trimethylated chitosan for nasal administration: effect of concentration and molecular weight
The Indonesian archipelago is characterized by strong internal tides, which are trapped in the different semi-enclosed seas of the archipelago. Using tidal model results a parameterization of the associated 3d tidal mixing is developed. The resulting average vertical diffusivity is 1.5 cm2/s, which independently agrees with the estimates inferred from observations. Introduced in a regional OGCM, the parameterization improves the water mass characteristics in the different Indonesian seas, suggesting that the horizontal and vertical distributions of the mixing are adequately prescribed. In particular, the salinity maximum of the inflow water is reduced along the main route, mainly in the Dewakang sill area. But also it is erased in the Halmahera and Seram seas, the entrance of the eastern route, so that salty waters doesn't penetrate the Banda Sea. As a result the simulated Indonesian Throughflow Water are in good agreement with observations. <br/
How sugar types and fabrication methods affect palatability in paediatric-friendly oromucosal pullulan films of chlorpromazine hydrochloride
Ensuring children adhere to their prescribed medication can be challenging, particularly when a large number of medicines on the market consist of unpalatable drugs and difficult to swallow dosage forms. Sugar-based oromucosal films are easy to administer dosage forms across all age groups within the paediatric population, as they eliminate the need for swallowing or water intake and can contribute to enhancing palatability and medicine adherence. In the current study, electrospun and 3D printed oromucosal films of chlorpromazine hydrochloride (CHZ), a bitter drug, were developed based on pullulan, a natural polysaccharide, and an array of sweeteners. Their taste masking efficacy was assessed in vitro using an electronic tongue, showing a significant suppression of the bitter taste of CHZ in the presence of sucralose, sucrose and isomalt in the 3D-printed films. In vivo assessment further confirmed that the sugar-based 3D printed films are highly acceptable to volunteers. For the electrospun films, volunteers reported neutral responses for overall acceptability, likely due to their lack of familiarity with this type of formulation. Overall, with improved acceptability and further optimization for taste masking, sugar-based films could serve as a viable alternative to conventional solid oral dosage forms for administering drugs to children
Preparation and characterization of multiactive electrospun fibers:Poly-ε-carpolactone fibers loaded with hydroxyapatite and selected NSAIDs
Electrospun poly-ε-caprolactone fibers were employed as hosts for hydroxypatite and nonsteroidal anti-inflammatory drugs (NSAIDs) ibuprofen (IBU) and indomethacin (INDO) (separately). The fibers (size range between 400 and 20 μm) were characterized by means of X-ray diffraction, differential scanning calorimetry, fourier-transform infrared spectroscopy and scanning electron microscopy. The physicochemical characterization of the fibers indicated that the drugs are associated with the fibers in an amorphous state. The release of IBU and INDO was monitored in PBS pH 7.4. A rapid release was observed for both drugs. Finally, bioactivity studies in simulated body fluid revealed the formation of hydroxyapatite, indicating that the fibers could be further utilized as materials for coupled (or multipurpose) biomedical and biomaterial engineering applications. © 2013 Wiley Periodicals, Inc
Survival and proliferation under severely hypoxic microenvironments using cell-laden oxygenating hydrogels
Different strategies have been employed to provide adequate nutrients for engineered living tissues. These have mainly revolved around providing oxygen to alleviate the effects of chronic hypoxia or anoxia that result in necrosis or weak neovascularization, leading to failure of artificial tissue implants and hence poor clinical outcome. While different biomaterials have been used as oxygen generators for in vitro as well as in vivo applications, certain problems have hampered their wide application. Among these are the generation and the rate at which oxygen is produced together with the production of the reaction intermediates in the form of reactive oxygen species (ROS). Both these factors can be detrimental for cell survival and can severely affect the outcome of such studies. Here we present calcium peroxide (CPO) encapsulated in polycaprolactone as oxygen releasing microparticles (OMPs). While CPO releases oxygen upon hydrolysis, PCL encapsulation ensures that hydrolysis takes place slowly, thereby sustaining prolonged release of oxygen without the stress the bulk release can endow on the encapsulated cells. We used gelatin methacryloyl (GelMA) hydrogels containing these OMPs to stimulate survival and proliferation of encapsulated skeletal myoblasts and optimized the OMP concentration for sustained oxygen delivery over more than a week. The oxygen releasing and delivery platform described in this study opens up opportunities for cell-based therapeutic approaches to treat diseases resulting from ischemic conditions and enhance survival of implants under severe hypoxic conditions for successful clinical translation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]