Intraoperative mapping and preservation of executive functions in awake craniotomy: a systematic review.

Awake craniotomy (AC) allows intraoperative brain mapping (ioBM) for maximum lesion resection while monitoring and preserving neurological function. Conventionally, language, visuospatial assessment, and motor functions are mapped, while the assessment of executive functions (EF) is uncommon. Impaired EF may lead to occupational, personal, and social limitations, thus, a compromised quality of life. A comprehensive literature search was conducted through Scopus, Medline, and Cochrane Library using a pre-defined search strategy. Articles were selected after duplicate removal, initial screening, and full-text assessment. The demographic details, ioBM techniques, intraoperative tasks, and their assessments, the extent of resection (EOR), post-op EF and neurocognitive status, and feasibility and potential adverse effects of the procedure were reviewed. The correlations of tumor locations with intraoperative EF deficits were also assessed. A total of 13 studies with intraoperative EF assessment of 351 patients were reviewed. Awake-asleep-awake protocol was most commonly used. Most studies performed ioBM using bipolar stimulation, with a frequency of 60 Hz, pulse durations ranging 1-2 ms, and intensity ranging 2-6 mA. Cognitive function was monitored with the Stroop task, spatial-2-back test, line-bisection test, trail-making-task, and digit-span tests. All studies reported similar or better EOR in patients with ioBM for EF. When comparing the neuropsychological outcomes of patients with ioBM of EF to those without it, all studies reported significantly better EF preservation in ioBM groups. Most authors reported EF mapping as a feasible tool to obtain satisfactory outcomes. Adverse effects included intraoperative seizures which were easily controlled. AC with ioBM of EF is a safe, effective, and feasible technique that allows satisfactory EOR and improved neurocognitive outcomes with minimal adverse effects.

Sterilization effects on poly(glycerol dodecanedioate): A biodegradable shape memory elastomer for biomedical applications.

Biodegradable shape memory polymers provide unique regenerative medicine approaches in minimally invasive surgeries. Once heated, thermally responsive shape memory polymer devices can be compressed, programmed to fit within a small profile, delivered in the cold programmed state, and expanded when heated to body temperature. We have previously developed a biodegradable shape memory elastomer (SME), poly(glycerol dodecanedioate) (PGD), with transition temperatures near 37°C exhibiting nonlinear elastic properties like numerous soft tissues. Using SMEs in the clinic requires disinfection and sterilization methods that conserve physiochemical, thermomechanical, and shape recovery properties. We evaluated disinfection protocols using 70% ethanol and UV254 nm for research applications and ethylene oxide (EtO) gas sterilization for clinical applications. Samples disinfected with ethanol for 0.5 and 1 min showed no changes in physiochemical material properties, but after 15 min showed slower recovery rates than controls (p < .05). EtO sterilization at 54.4°C decreased transition temperatures and shape recovery rate compared to EtO sterilization at 37.8°C (p < .01) and controls (p < .05). Aging samples for 9 months in a vacuum desiccator significantly reduced shape recovery, and the recovery rate in EtO sterilized samples compared to controls (p < .001). Cytotoxicity testing (ISO-10993.5C:2012) revealed media extractions from EtO sterilized samples, sterilized at 37.8°C, and high-density polyethylene negative control samples exhibit lower cytotoxicity (IC50) than Ethanol 1 min, UV 2 h, and EtO 54.4°C. Cell viability of NIH3T3 fibroblasts on sterilized surfaces was equivalent on EtO 37.7°C, EtO 54.4°C and Ethanol sterilized substrates. Finally, chromogenic bacterial endotoxin testing showed endotoxin levels were below the FDA prescribed levels for devices contacting blood and lymphatic tissues for ethanol 1 min, UV 120 min, EtO 37.7°C, EtO 54.4°C. These findings outline various disinfection and sterilization processes for research and pre-clinical application and provide a pathway for developing custom sterilization cycles for the translation of biomedical devices utilizing PGD shape memory polymers.

Tumor-Associated Macrophages and Ovarian Cancer: Implications for Therapy.

The tumor microenvironment (TME) has been implicated to play an important role in the progression of ovarian cancer. One of the most important components of the TME is tumor associated macrophages (TAMs). Phenotypically, macrophages are broadly categorized as M1 pro-inflammatory or M2 anti-inflammatory, based on the cytokines and chemokines that they secrete. The tumor microenvironment is associated with macrophages of an M2 phenotype which suppress the surrounding immune environment, assist tumor cells in evading immune targeting, and support tumor growth and metastasis. Contrarily, M1 macrophages help mount an immune response against tumors, and are associated with a more favorable prognosis in solid tumors. One of the characteristic indicators of a poor prognosis in ovarian cancer is the overrepresentation of M2-type TAMs. As such, therapeutic modalities targeting TME and TAMs are of increasing interest. Pharmacological approaches to eliminate TAMs, include decreasing macrophage survival and recruitment and increasing phagocytosis, have been underwhelming. Clinical strategies targeting these macrophage subtypes via repolarization to an M1 antitumoral state deserve increasing attention, and may serve as a new modality for immunotherapy.