Sulfated Hydrogels in Intervertebral Disc and Cartilage Research.

Hydrogels are commonly used for the 3D culture of musculoskeletal cells. Sulfated hydrogels, which have seen a growing interest over the past years, provide a microenvironment that help maintain the phenotype of chondrocytes and chondrocyte-like cells and can be used for sustained delivery of growth factors and other drugs. Sulfated hydrogels are hence valuable tools to improve cartilage and intervertebral disc tissue engineering. To further advance the utilization of these hydrogels, we identify and summarize the current knowledge about different sulfated hydrogels, highlight their beneficial effects in cartilage and disc research, and review the biofabrication processes most suitable to secure best quality assurance through deposition fidelity, repeatability, and attainment of biocompatible morphologies.

Thermoplastic Blend Exhibiting Shape Memory-Assisted Self-Healing Functionality.

Here, we report on a polymer blend consisting of a soft thermoplastic polyurethane (TPU) elastomer and a low melting temperature thermoplastic healing agent (polycaprolactone, PCL). In this study, polymer blends containing up to 60 wt % PCL were prepared and the resulting mechanical, thermal, shape memory, and self-healing properties were studied. These immiscible polymers exhibit two well-separated transitions attributable to the melting of PCL and TPU hard segments. This viscoelastic behavior engendered shape memory capability at moderate processing temperatures (∼90 °C) and melt processability at elevated temperatures (>160 °C). The reversible plasticity shape memory (RPSM) effect was also characterized: when subjected to 125% strain at room temperature and subsequently heated to 90 °C, the samples nearly fully recovered to their original length. Moreover, upon heating to above PCL's melting temperature, the flow of PCL into an undeformed crack was shown to fill the crack void, thus promoting self-repair. Through the action of mild heating (90 °C/30 min), fracture surfaces are brought into intimate contact through the action of the RPSM effect and subsequently healed through the redistribution of molten PCL. The shape memory-assisted self-healing efficiency was evaluated by comparing the tensile force restoration after healing of a highly deformed, notched sample to its behavior prior to notching. It was observed that blends containing up to 30 wt % PCL showed nearly complete restoration of properties. In contrast, pure TPU showed only about 5% healing efficiency because of the absence of the PCL healing agent. Blends containing 50 and 60 wt % PCL likewise did not exhibit appreciable restoration of properties, and this was attributed to their propensity to neck during crack opening and poor mechanical properties at elevated temperatures. Blends may serve as a self-healing replacement for pure TPU in existing applications (e.g., automotive and sporting goods) or as a self-healing shape memory polymer in advanced products in soft robotic, biomedical, and microelectronic applications.

Complications associated with anesthesia administered for dental treatment.

This assessment sought to identify and quantify complications that occur with anesthesia administration during dental treatment of consecutive patients who received care through the University of Pittsburgh School of Dental Medicine's (UPSDM) Department of Anesthesiology. This prospective study was completed by participating anesthesia caregivers at the UPSDM as a case-by-case evaluation. A standardized form delineating possible complications was used to collect data following 286 consecutive outpatient anesthetic cases administered within the UPSDM. After statistical analysis of five types of administered anesthesia, the overall complication rate was 22.4% in 286 cases. All of the complications were considered to be mild (90.6%) or moderate (9.4%); there were no reports of severe complications. The complications encountered most frequently were airway obstruction (18 reports) and occurrence of nausea/vomiting (12 reports). ASA classification, anesthetic technique, pre-existing medical findings, and the type of dental procedure performed all were variables that were found to affect the incidence of anesthesia-related complications. The overall complication rate from anesthesia administered during dental care is similar to or less than that reported within the hospital operating system environment.

Complications associated with anesthesia administration for dental treatment in a special needs clinic.

The goal of this study was to identify and quantify complications occurring with the administration of anesthesia for the dental treatment of patients with special needs. Anesthesia providers completed a standardized evaluation form, delineating possible complications for 202 consecutive ambulatory patients receiving anesthesia in a special needs clinic. Statistical analysis of four types of administered anesthesia showed that the overall complication rate was 23.8%. Evaluation of the data showed complications that were considered either mild (95.8%), or moderate (4.2%), while no reports of severe complications occurred. Airway obstruction and nausea/vomiting were the most frequently encountered complications. Variables found to affect the incidence of anesthetic complications included ASA classification, anesthetic technique, Mallampati airway classification, and type of dental procedure performed. An evaluation of the results of the study showed that the majority of complications that occurred with anesthesia during care of patients with special needs were mild and did not lead to severe adverse events. Our findings show that anesthesia administered during dental treatment for patients with special needs is safe and effective.