Fast three-dimensional micropatterning of PC12 cells in rapidly crosslinked hydrogel scaffolds using ultrasonic standing waves.

The ability to spatially organise the microenvironment of tissue scaffolds unlocks the potential of many scaffold-based tissue engineering applications. An example application is to aid the regeneration process of peripheral nerve injuries. Herein, we present a promising approach for three-dimensional (3D) micropatterning of nerve cells in tissue scaffolds for peripheral nerve repair. In particular, we demonstrate the 3D micropatterning of PC12 cells in a gelatin-hydroxyphenylpropionic acid (Gtn-HPA) hydrogel using ultrasound standing waves (USWs). PC12 cells were first aligned in 3D along nodal planes by the USWs in Gtn-HPA hydrogel precursor solution. The precursor was then crosslinked using horseradish peroxidase (HRP) and diluted hydrogen peroxide (H2O2), thus immobilising the aligned cells within 90-120 s. This micropatterning process is cost effective and can be replicated easily without the need for complex and expensive specialised equipment. USW-aligned PC12 cells showed no adverse effect in terms of viability or ability to proliferate. To our best knowledge, this is the first report on the effect of USW alignment on neural cell differentiation. Differentiated and USW-aligned PC12 cells showed directional uniformity after 20 d, making this technique a promising alternative approach to guide the nerve regeneration process.

Factors influencing ICU admission and associated outcome in patients undergoing radical cystectomy with enhanced recovery pathway.

PURPOSE: To characterize drivers of ICU admission during index hospitalization after Radical Cystectomy (RC) with Enhanced Recovery After Surgery (ERAS) protocol, as well as corresponding outcomes. METHODS: A retrospective review of an IRB-approved cystectomy database was conducted. All patients who underwent RC with ERAS protocol from 2012 to 2017 were included. EXCLUSION CRITERIA: adjunct nephrectomy or urethrectomy. RESULTS: A total of 512 patients were identified. ICU admission in index hospitalization was reported in 33 patients (6.4%), 26 with unplanned ICU transfer after initial non-ICU level of care and 7 with planned direct postoperative ICU admission. Higher age and Charlson Comorbidity Index ≥3 were significant risk factors for unplanned ICU admission. On multivariate analysis, age remained associated (odds ratio 1.05, 95% confidence interval 1.008, 1.1, P = 0.02) and Charlson Comorbidity Index ≥3 kept the trend (odds ratio 2.16, 95% confidence interval 0.86 - 5.07, P = 0.08) with this increased risk of ICU admission. Patients in the unplanned ICU group spent a median of 3 days (range: 0-32) at non-ICU level of care before ICU transfer; cardiac indications were the most common reason for transfer (52%). Patients who required unplanned ICU transfer had a median length of stay of 11.5 days, compared to a length of stay of 5 days (P < 0.01) for non-ICU patients. Ninety-day readmission and mortality rates were higher in the planned ICU cohort when compared to the unplanned ICU cohort. A low rate of ICU admission (2.7%) in the corresponding 90-day postoperative period was reported for the group not requiring ICU admission during index hospitalization. CONCLUSION: ICU admission is uncommon following RC with ERAS protocol. Advanced age and comorbidity index are significantly associated with unplanned ICU transfer. Planned ICU admissions are not shown to be associated with improved outcomes compared to unplanned ICU admissions. Further efforts to elucidate the role of ICU care in the context of the ERAS protocol is important for targeted care optimization and appropriate postoperative planning.