Controlled release of analgesic drugs from porous bioresorbable structures for various biomedical applications

Pain is one of the most common patient complaints encountered by health professionals and remains the number one cause of absenteeism and disability. In the current study, analgesic-eluting bioresorbable porous structures prepared using the freeze-drying of inverted emulsions technique were developed and studied. These drug-eluting structures can be used for coating fibers or implants, or for creating standalone films. They are ideal for forming biomedically important structures that can be used for various applications, such as wound dressings that provide controlled release of analgesics to the wound site in addition to their wound dressing role. Our investigation focused on the effects of the inverted emulsion's parameters on the shell microstructure and on the resulting drug-release profile of ibuprofen and bupivacaine. The release profiles of ibuprofen formulations exhibited a diffusion-controlled pattern, ranging from several days to 21 days, whereas bupivacaine formulations exhibited an initial burst release followed by a three-phase release pattern over a period of several weeks. Higher organic to aqueous phase ratios and higher polymer contents reduced the burst release of both drugs and prolonged their release due to lower porosity. Overall, the drug-eluting porous structures loaded with either ibuprofen or bupivacaine demonstrated a promising potential for use in various applications that require pain relief

Natural high pCO2 increases autotrophy in Anemonia viridis (Anthozoa) as revealed from stable isotope (C, N) analysis

Contemporary cnidarian-algae symbioses are challenged by increasing CO2 concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural pCO2 gradient at the island of Vulcano, Italy. delta 13C values for both algal symbionts (Symbiodinium) and host tissue of A. viridis became significantly lighter with increasing seawater pCO2. Together with a decrease in the difference between delta 13C values of both fractions at the higher pCO2 sites, these results indicate there is a greater net autotrophic input to the A. viridis carbon budget under high pCO2 conditions. delta 15N values and C/N ratios did not change in Symbiodinium and host tissue along the pCO2 gradient. Additional physiological parameters revealed anemone protein and Symbiodinium chlorophyll a remained unaltered among sites. Symbiodinium density was similar among sites yet their mitotic index increased in anemones under elevated pCO2. Overall, our findings show that A. viridis is characterized by a higher autotrophic/heterotrophic ratio as pCO2 increases. The unique trophic flexibility of this species may give it a competitive advantage and enable its potential acclimation and ecological success in the future under increased ocean acidification

Physiological and isotopic responses of scleractinian corals to ocean acidification

Uptake of anthropogenic CO2 by the oceans is altering seawater chemistry with potentially serious consequences for coral reef ecosystems due to the reduction of seawater pH and aragonite saturation state (Omega(arag)) The objectives of this long-term study were to investigate the viability of two ecologically important reef-building coral species, massive Ponies sp. and Stylophora pistillata, exposed to high pCO(2) (or low pH) conditions and to observe possible changes in physiologically related parameters as well as skeletal isotopic composition. Fragments of Ponies sp. and S. pistillata were kept for 6-14 months under controlled aquarium conditions characterized by normal and elevated pCO(2) conditions, corresponding to pH(T) values of 8.09, 7.49, and 7.19, respectively. In contrast with shorter, and therefore more transient experiments, the long experimental time-scale achieved in this study ensures complete equilibration and steady state with the experimental environment and guarantees that the data provide insights into viable and stably growing corals. During the experiments, all coral fragments survived and added new skeleton, even at seawater Omega(arag) = 1. The delta B-11 vs. pH offset from the seawater delta B-11 vs. pH fractionation curves suggests a change in the ratio of skeletal material laid down during dark and light calcification and/or an internal pH regulation, presumably controlled by ion-transport enzymes. Finally, seawater pH significantly influences skeletal delta C-13 and delta O-18. This must be taken into consideration when reconstructing paleo-environmental conditions from coral skeletons. (C) 2010 Elsevier Ltd. All rights reserved

Free‐floating medial meniscus implant kinematics do not change after simulation of medial open‐wedge high tibial osteotomy and notchplasty

Abstract Purpose The purpose of this in‐vitro study was to examine the kinematics of an artificial, free‐floating medial meniscus replacement device under dynamic loading situations and different knee joint states. Methods A dynamic knee simulator was used to perform dynamic loading exercises on three neutrally aligned and three 10° valgus aligned (simulating a medial openwedge high tibial osteotomy ‐ MOWHTO) left human cadaveric knee joints. The knee joints were tested in three states (intact, conventional notchplasty, extended notchplasty) while 11 randomised exercises were simulated (jump landing, squatting, tibial rotation and axial ground impacts at 10°, 30° and 60° knee joint flexion) to investigate the knee joint and implant kinematics by means of rigidly attached reflective marker sets and an according motion analysis. Results The maximum implant translation relative to the tibial plateau was < 13 mm and the maximum implant rotation was < 19° for all exercises. Both, the notchplasties and the valgus knee alignment did not affect the device kinematics. Conclusions The results of the present in‐vitro study showed that the non‐anchored free‐floating device remains within the medial knee joint gap under challenging dynamic loading situations without indicating any luxation tendencies. This also provides initial benchtop evidence that the device offers suitable stability and kinematic behaviour to be considered a potential alternative to meniscus allograft transplantation in combination with an MOWHTO, potentially expanding the patient collective in the future