A Novel Intervention Technology for Cerebral Palsy: Brain Stimulation

Abstract:A common pediatric disorder with posture and motor dysfunctionin neurological diseases is known as cerebral palsy (CP). Recently,a series of effective techniques have been developed for treatmentof CP. These promising methods need high-tech equipment forbrain stimulation and mainly classified into invasive and noinvasiveapproaches. This study aimed to introduce these techniquesfor treatment of patients who suffer from CP. The potential andperformance of currently available brain stimulation techniques havebeen mentioned in detail. Moreover, the clinical application, safety,efficacy and challenges of these methods have been discussed. Herewe review the recent advances in the CP treatment with an emphasison brain stimulation techniquesKeywords:Cerebral palsy; Brain stimulation; Pediatric disorde

Additive manufacturing of bioactive glass biomaterials

AbstractTissue engineering (TE) and regenerative medicine have held great promises for the repair and regeneration of damaged tissues and organs. Additive manufacturing has recently appeared as a versatile technology in TE strategies that enables the production of objects through layered printing. By applying 3D printing and bioprinting, it is now possible to make tissue-engineered constructs according to desired thickness, shape, and size that resemble the native structure of lost tissues. Up to now, several organic and inorganic materials were used as raw materials for 3D printing; bioactive glasses (BGs) are among the most hopeful substances regarding their excellent properties (e.g., bioactivity and biocompatibility). In addition, the reported studies have confirmed that BG-reinforced constructs can improve osteogenic, angiogenic, and antibacterial activities. This review aims to provide an up-to-date report on the development of BG-containing raw biomaterials that are currently being employed for the fabrication of 3D printed scaffolds used in tissue regeneration applications with a focus on their advantages and remaining challenges.Abstract Tissue engineering (TE) and regenerative medicine have held great promises for the repair and regeneration of damaged tissues and organs. Additive manufacturing has recently appeared as a versatile technology in TE strategies that enables the production of objects through layered printing. By applying 3D printing and bioprinting, it is now possible to make tissue-engineered constructs according to desired thickness, shape, and size that resemble the native structure of lost tissues. Up to now, several organic and inorganic materials were used as raw materials for 3D printing; bioactive glasses (BGs) are among the most hopeful substances regarding their excellent properties (e.g., bioactivity and biocompatibility). In addition, the reported studies have confirmed that BG-reinforced constructs can improve osteogenic, angiogenic, and antibacterial activities. This review aims to provide an up-to-date report on the development of BG-containing raw biomaterials that are currently being employed for the fabrication of 3D printed scaffolds used in tissue regeneration applications with a focus on their advantages and remaining challenges

Timing of surgery following SARS-CoV-2 infection:an international prospective cohort study

Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. From 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odd ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odd ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.</p

Microfluidic 3D Cell Culture: Potential Application of Collagen Hydrogels with an Optimal Dose of Bioactive Glasses

We engineered a microfluidic platform to study the effects of bioactive glass nanoparticles (BGNs) on cell viability under static culture. We incorporated different concentrations of BGNs (1%, 2%, and 3% w/v) in collagen hydrogel (with a concentration of 3.0 mg/mL). The microfluidic chip's dimensions were optimized through fluid flow and mass transfer simulations. Collagen type I extracted from rat tail tendons was used as the main material, and BGNs synthesized by the sol-gel method were used to enhance the mechanical properties of the hydrogel. The extracted collagen was characterized using FTIR and SDS-PAGE, and BGNs were analyzed using XRD, FTIR, DLS, and FE-SEM/EDX. The structure of the collagen-BGNs hydrogels was examined using SEM, and their mechanical properties were determined using rheological analysis. The cytotoxicity of BGNs was assessed using the MTT assay, and the viability of fibroblast (L929) cells encapsulated in the collagen-BGNs hydrogel inside the microfluidic device was assessed using a live/dead assay. Based on all these test results, the L929 cells showed high cell viability in vitro and promising microenvironment mimicry in a microfluidic device. Collagen3-BGNs3 (Collagen 3 mg/mL + BGNs 3% (w/v)) was chosen as the most suitable sample for further research on a microfluidic platform

Additively manufactured small-diameter vascular grafts with improved tissue healing using a novel SNAP impregnation method

The vascular network has a complex architecture such as branches, curvatures, and bifurcations which is even more complicated in view of individual patients' defect anatomy requiring custom-specifically designed vascular implants. In this work, 3D printing is used to overcome these challenges and a new shorter impregnation method was developed to incorporate S-nitroso-N-acetyl-d-penicillamine (SNAP) as a nitric oxide (NO) donor to printed grafts. The 3D-printed small-diameter vascular grafts (SDVGs) were impregnated with SNAP solution during SNAP synthesis (S1) or with SNAP dissolved in methanol (S2). The advantage of the newly developed S1 impregnation method is the elimination of the synthesis step by direct impregnation inside the S1 solution. Scanning electron microscopy imaging reveals the successful crystal formation in both methods. The results demonstrate that both S1- and S2-impregnated grafts, after covering with polycaprolactone topcoat, can release NO in a controlled manner and in the physiological range (0.5-4.0 × 10-10 mol cm-2 min-1 ) over a 15 days period. The created grafts with a NO-releasing surface have also shown bactericidal effect while the healing properties of the implant were improved by promoting migration and proliferation of endothelial cells (ECs). These results suggest that incorporation of 3D printing technology with the newly developed S1 impregnation of SNAP can optimize and shorten the manufacturing process of the next generation of patient-based antibacterial SDVGs with a higher attraction for ECs.status: publishe