Herein, we report the development of a highly sensitive nanotechnology-based system—silicon-on-insulator nanowire biosensor for the revelation of microRNAs (miRNAs), associated with the development of glioma in the human. In this system, a sensor chip, bearing an array of silicon nanowire structures, is employed. The sensor chip is fabricated using a top-down technology. In our experiments reported herein, we demonstrated the detection of DNA oligonucleotide (oDNA), which represents a synthetic analogue of microRNA-363 associated with the development of glioma. To provide biospecific detection of the target oligonucleotides, the surface of the nanowire structures is modified with oligonucleotide probes; the latter are complementary to the target ones. The concentration limit of the target oligonucleotide detection, attained using our nanowire biosensor, is at the level of DL~10−17 M. The revelation of the elevated level of glioma-associated miRNA in plasma is also demonstrated.

Nanoribbon chips, based on “silicon-on-insulator” structures (SOI-NR chips), have been fabricated. These SOI-NR chips, whose surface was sensitized with covalently immobilized oligonucleotide molecular probes (oDNA probes), have been employed for the nanoribbon biosensor-based detection of a circular ribonucleic acid (circRNA) molecular marker of glioma in humans. The nucleotide sequence of the oDNA probes was complimentary to the sequence of the target oDNA. The latter represents a synthetic analogue of a glioma marker—NFIX circular RNA. In this way, the detection of target oDNA molecules in a pure buffer has been performed. The lowest concentration of the target biomolecules, detectable in our experiments, was of the order of ~10−17 M. The SOI-NR sensor chips proposed herein have allowed us to reveal an elevated level of the NFIX circular RNA in the blood of a glioma patient.

BACKGROUND: Postoperative infections after brain surgery are a serious complication potentially worsening the outcome of surgical treatment. Severe intraoperative hyperglycemia (SIH) contributes to both infectious and noninfectious postoperative complications. However, there are a lack of data on the incidence of SIH in patients undergoing elective neurosurgical brain procedures and its association with the risk of postoperative infections. METHODS: A total of 514 patients were prospectively enrolled in this single-center observational cohort clinical study to assess the incidence of SIH (blood glucose concentration [BGC] ≥180 mg/dL) in adult patients undergoing elective brain neurosurgical procedures and its association with postoperative infections. Both nondiabetic and diabetic patients were included in the study. BGC was determined by whole-blood analyses taken at the beginning and at the end of the surgery. Diagnosis of infection (wound, pulmonary, blood stream, urinary tract infection, or central nervous system infection) was established according to US Centers for Disease Control and Prevention (CDC) criteria within the first postoperative week. RESULTS: SIH was recorded in at least 1 blood sample in 23 patients (4.5%). Infectious complications within the first postoperative week were diagnosed in 40 patients (7.8%). Five of 23 patients (22%) with SIH had postoperative infections, compared with 35 of 491 patients (7%) without SIH (odds ratio [OR] = 3.71; 95% confidence interval [CI], 1.24–11.09; P = .018 after fitting a multiple logistic regression model to adjust for age, body mass index [BMI], and surgery duration). Intraoperative BGC >140 mg/dL was also associated with an increased risk of postoperative infections (OR = 3.10; 95% CI, 1.43–6.75; P = .004). Elevated preoperative glycated hemoglobin (HbA1c) concentration was also associated with postoperative infections in the study population (OR = 2.4; 95% CI, 1.02–6.00; P = .045). Age, BMI, American Society of Anesthesiologists (ASA) physical status, type of surgery, and duration of intervention had no significant association with the postoperative infection rate. CONCLUSIONS: SIH is associated with a higher risk of infections within the first postoperative week in patients undergoing elective brain neurosurgical procedures. Preoperative HbA1c is a reliable marker of the potential risk both of SIH and postoperative infections in the selected cohort. Future studies need to assess possible improvements in outcome under more precise monitoring and tighter control of perioperative hyperglycemia.