Chitosan-based multifunctional hydrogel with bio-adhesion and antioxidant properties for efficient wound hemostasis.

Benefiting from the biocompatibility, adhesiveness, and natural extracellular matrix-mimicking ability, hydrogels have received increasing research in recent years. In this study, a hydrogel system composed of dopamine, quaternized ammoniated chitosan (QCS), and polyvinylpyrrolidone was reported to exhibit fast hemostatic properties in Sprague-Dawley rat tail amputation and liver bleeding models. The results showed that this hydrogel had good hemostatic properties. The designed hydrogel showed high swelling ratios in H2O, PBS, and 0.9 % NaCl solution, indicating its capability to absorb tissue residual exudate and form a stable hydrogel. Compared with the control group, the blood loss in Sprague-Dawley rat tail amputation and liver bleeding were reduced by nearly 78 % and 76 %, respectively. Interestingly, dopamine endowed the hydrogel with antioxidant properties, thus holding a great application promise in inflammatory wounds. Furthermore, the designed hydrogel demonstrated good and reversible adhesion properties (12.23 ± 0.22 kPa-24.31 ± 0.55 kPa), ensuring its firm attachment to bleeding wounds of pig skin in wet environments. This research points out a novel path for designing chitosan-based hydrogels for biomedical applications.

Preparation of Multi-Functional Quaternary Ammonium Chitosan/Surfactin Hydrogel and its Application in Wound Management.

Hydrogel with a 3D network structure can cover the wound to stop the bleeding and support the host tissue infiltration and integration. In this study, an antibacterial hydrogel with hemostasis and the ability to promote wound healing is proposed. This hydrogel comprised surfactin, polyvinylpyrrolidone, and methacrylic anhydride (MA) grafted quaternary ammonium chitosan (CS-MA). The hydrogel formation is triggered by the ultraviolet-initiated polymerization of CS-MA, while the surfactin is complexed with the hydrogel through hydrogen bonding interaction. The results showed that this hydrogel is an adhesive hydrogel with shape adaptability, which can cover the wound surface and promote contact between the hydrogel and the wound surface. More importantly, this hydrogel can simulate the microenvironment of the primary extracellular matrix and increase collagen deposition, and inflammatory factor transformation. The designing of such a multi-functional hydrogel is expected to provide a novel approach to promoting the healing of wounds.

Examining the function of macrophage oxidative stress response and immune system in glioblastoma multiforme through analysis of single-cell transcriptomics.

Background: Glioblastoma (GBM), a prevalent malignant neoplasm within the neuro-oncological domain, has been a subject of considerable scrutiny. Macrophages, serving as the principal immunological constituents, profoundly infiltrate the microenvironment of GBM. However, investigations elucidating the intricate immunological mechanisms governing macrophage involvement in GBM at the single-cell level remain notably limited. Methods: We conducted a comprehensive investigation employing single-cell analysis, aiming to redefine the intricate cellular landscape within both the core and peripheral regions of GBM tumors. Our analytical focus extended to the profound study of macrophages, elucidating their roles within the context of oxidative stress, intercellular information exchange, and cellular trajectories concerning GBM and its assorted subpopulations. We pursued the identification of GBM prognostic genes intricately associated with macrophages. Utilizing experimental research to investigate the relevance of MANBA in the context of GBM. Results: Our investigations have illuminated the central role of macrophages in the intricate interplay among various subpopulations within the GBM microenvironment. Notably, we observed a pronounced intensity of oxidative stress responses within macrophages when compared to their GBM counterparts in other subpopulations. Moreover, macrophages orchestrated intricate cellular communication networks, facilitated by the SPP1-CD44 axis, both internally and with neighboring subpopulations. These findings collectively suggest the potential for macrophage polarization from an M1 to an M2 phenotype, contributing to immune suppression within the tumor microenvironment. Furthermore, our exploration unearthed GBM prognostic genes closely associated with macrophages, most notably MANBA and TCF12. Remarkably, MANBA appears to participate in the modulation of neuroimmune functionality by exerting inhibitory effects on M1-polarized macrophages, thereby fostering tumor progression. To bolster these assertions, experimental validations unequivocally affirmed the promotional impact of MANBA on GBM, elucidated through its capacity to curb cell proliferation, invasiveness, and metastatic potential. Conclusion: These revelations represent a pivotal step towards unraveling the intricate immunological mechanisms governing the interactions between macrophages and diverse subpopulations within the GBM milieu. Furthermore, they lay the foundation for the development of an innovative GBM prognostic model, with MANBA at its epicenter, and underscore the potential for novel immunotherapeutic targets in the ongoing pursuit of enhanced treatment modalities for this formidable malignancy.

One-stage coiling versus clipping of multiple intracranial aneurysms in elderly patients.

OBJECTIVES: Although multiple intracranial aneurysms (MIAs) are frequent and disastrous, determining treatment strategy for them is often complicated, especially in elderly patients (≥60 years old). We evaluated the safety and effectiveness of one-stage coiling versus surgical clipping for MIAs in elderly patients. METHODS: All elderly patients who underwent one-stage embolization or surgical clipping for more than two aneurysms were identified in our hospital between January 2012 and June 2018. Patient characteristics and clinical outcomes at discharge and follow-up were retrospectively evaluated. RESULTS: A total of 32 patients with 76 IAs underwent one-stage coiling and 21 patients with 46 IAs underwent one-stage clipping were enrolled in this study. Patients who underwent clipping were younger (mean age 64.1 versus 67.2, P = 0.006) and had lower total hospital costs (mean14764 $ versus 24,620 $, P < 0.001) compared with patients who underwent coiling. Immediate posttreatment angiography showed complete occlusion in 56 aneurysms, near complete in 11 and incomplete in 2 in coiling group. Aneurysms wrapping was performed in 2, incomplete clipping in 1 and complete clipping in 41 aneurysms in clipping group. At discharge, 49 (92.5 %) patients were in a good condition (GOS score 4 and 5), 4 (7.5 %) were disabled. At 12 months after discharge, 25 (92.6 %) and 16 (94.1 %) patients had favorable outcomes in the coiling and clipping groups, respectively. CONCLUSIONS: Both one-stage coiling and surgical clipping are safe, effective methods for treating MIAs in elderly patients.

Optical Coherence Tomography for Intracranial Aneurysms: A New Method for Assessing the Aneurysm Structure.

BACKGROUND: There is a lack of precise methods for predicting the risk of aneurysm rupture. Therefore, prophylactic treatment is used, which leads to unnecessary potential complications. A new modality enabling a more accurate risk assessment is needed. Optical coherence tomography (OCT) is a new-generation imaging technology that has astonishing resolution for vascular imaging. In this study, OCT was used for the evaluation of intracranial aneurysms. METHODS: In vivo OCT imaging was performed for aneurysms induced in 6 rabbits and in 9 intracranial aneurysm patients. Catheters were cut short to prevent any extra length from damaging aneurysms and tissues. Images of both the parent artery and the aneurysm at multiple viewing angles were obtained using rotational OCT scanning. RESULTS: The OCT images of rabbits correlated well with histologic sections. The 3-layered architecture of the parent arteries was explicitly shown. Ruptured intracranial aneurysms manifested complete breakdown of the wall structure; however, this was not observed in any unruptured aneurysms. The OCT images of unruptured intracranial aneurysms demonstrated a trend of degradation by showing the gradual disappearance of the demarcation between the layers or incomplete apoptosis in layer structures. CONCLUSION: OCT is the most precise imaging modality because it provides detailed information regarding the aneurysm structures, thus enabling more distinct insight into the vascular construction of intracranial aneurysms.

Stent-assisted coiling embolization of tiny, wide-necked intracranial aneurysms.

BACKGROUND: Tiny, wide-necked intracranial aneurysms pose a significant therapeutic challenge for interventional neuroradiologists because of the small volume for microcatheterization and coil stabilization inside the aneurysm sac. We report our preliminary experience of stent-assisted coiling embolization of these aneurysms. METHODS: A total of 50 patients with 52 tiny, wide-necked aneurysms who were treated with stent-assisted coiling from January 2007 to December 2014 were reviewed retrospectively. Baseline characteristics, procedure-related complications, angiographic follow-up results and clinical outcomes were statistically analyzed. RESULT: All aneurysms were successfully treated with the stent-assisted coiling technique, and at the end of the procedure, aneurysm occlusion was complete for 45 (86.5 %), near complete for 3 (5.8 %) and incomplete for 4 (7.7 %). Procedural complications (1 intraprocedural rupture, 2 coil migrations and 1 aneurysm re-rupture) occurred in 4 (8 %) of 50 patients, resulting in permanent morbidity in 1 (2 %) patient and death in 1 (2 %) patient. Follow-up imaging was available in 43 (84.3 %) aneurysms for 6-31 months (mean, 13 months). Complete occlusion was achieved in 40 (93 %) of 43 aneurysms on long-term follow-up. One aneurysm with complete occlusion and one with incomplete occlusion after the initial embolization developed a significant recurrence (4.7 %). Clinical follow-up was available for 43 (86 %) of 50 patients at a mean of 36.7 months (range 15-66 months). Of these 43 patients, 42 (97 %) made an excellent recovery achieving a GOS of 5. None of the patients died or experienced re-bleeding or ischemic cerebral vascular events during follow-up. CONCLUSION: Stent-assisted coiling embolization is feasible and relatively safe for tiny, wide-necked intracranial aneurysms of carotid arteries. Furthermore, long-term follow-up angiography indicated stent-assisted coiling seems to be effective in preventing early recanalization.

Stent-Assisted Coiling of 501 Wide-Necked Intracranial Aneurysms: A Single-Center 8-Year Experience.

BACKGROUND: Stent-assisted coiling has expanded the treatment of complex wide-necked intracranial aneurysms. We present our experience with stent-assisted coiling, with an emphasis on procedure-related neurologic complications and the incidence of angiographic recurrence. METHODS: A total of 480 patients with 501 aneurysms who were treated with stent-assisted coiling between January 2007 and December 2014 were reviewed retrospectively. Baseline characteristics, procedure-related complications, angiographic follow-up results, and clinical outcomes were statistically analyzed. RESULTS: Among the 480 patients, 423 (88%) were treated electively and 57 (11%) were treated in the context of subarachnoid hemorrhage. There were 22 (4.58%) overall procedure-related complications, which caused death in 4 patients (0.83%) and morbidity in 4 patients (0.83%). In a logistic regression analysis, the complications differed significantly among the patients with hypertension (odds ratio [OR], 2.85; 95% confidence interval [CI], 1.09-7.48; P = 0.03), patients with aneurysms treated with coiling before stenting (OR, 3.07; 95% CI, 1.07-8.81; P = 0.04), and patients treated with multiple stents (OR, 4.96; 95% CI, 1.02-24.07; P = 0.04). Angiographic follow-up was available for 396 patients (83.4%) for a mean of 13 months. The rates of recanalization and retreatment were 13.9% and 3.5%, respectively. In a logistic analysis, larger aneurysm size and initial incomplete aneurysm occlusion were predictors of recanalization. Clinical follow-up was available for 406 patients (85.6%) for a mean of 44.8 months, and 399 patients (98.3%) achieved a Glasgow Outcome Scale score of 5. CONCLUSIONS: Stent-assisted coiling appears to be a safe and effective option for treating complex wide-necked aneurysms. Higher complication rates are associated with coiling before stenting, use of multiple stents, and hypertension. Stent delivery before coil deployment reduces the risk of procedural complications. Larger aneurysm size and initial incomplete occlusion are associated with aneurysm recanalization.

[Application of microarrays in screening the tumor-specific genes in the genome of K562 cells].

OBJECTIVE: To screen tumor-specific genes of K562 cells using DNA microarray technique. METHODS: The genomic DNA of normal white blood cells and cultured K562 cells were respectively purified and digested with Sau3A I, and the digested DNA fragments of K562 cells were cloned into TA cloning vector to construct the corresponding genomic DNA library. The insert genomic DNA fragments were amplified from the library to prepare the microarray using Cartesian 5500 Microarrayer. The digested genomic DNA fragments of normal white blood cells were labeled with fluorescent Cy3 by restriction display PCR (RD-PCR), followed by hybridization with the microarray, after which the slide was washed and scanned with ScanArray. RESULTS: Among the 426 target genes, 42 differential genes were identified in the genomic DNA of K562 cells in comparison with the normal white blood cells. One of the genes was identified as the breakpoint cluster gene (BCR) after sequence analysis. CONCLUSIONS: The DNA microarrays we constructed may effectively identify the tumor-specific genes in K562 cells, and DNA microarray technique can be helpful in elucidating the molecular mechanisms of tumorigenesis at the genomic level.

[Detection of cell apoptosis by MTT assay].

OBJECTIVE: To study the feasibility of using MTT assay to detect cell apoptosis. METHODS: K562 cells were grown in RPMI 1640 medium supplemented with 10% calf serum and 4 micromol/L arsenic trioxide. Apoptosis was induced in the cultured cells by As2O3, and the cells were detected with optical microscope, DNA gel electrophoresis and MTT staining respectively. RESULT: MTT staining could also accurately detect cell apoptosis, by which the apoptotic cells were easily distinguished from normal cells and dead cells. CONCLUSION: MTT staining is simple, convenient and practical for detecting cell apoptosis.