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ACS Nanoscience Au Aug 2023Developing new techniques to prepare free-standing tubular scaffolds has always been a challenge in the field of regenerative medicine. Here, we report a new and simple...
Developing new techniques to prepare free-standing tubular scaffolds has always been a challenge in the field of regenerative medicine. Here, we report a new and simple way to prepare free-standing collagen constructs with rolled-up architecture by self-assembling nanofibers on porous alumina (AlO) textiles modified with different silanes, carbon or gold. Following self-assembly and cross-linking with glutaraldehyde, collagen nanofibers spontaneously rolled up on the modified AlO textiles and detached. The resulting collagen constructs had an inner diameter of approximately 2 to 4 mm in a rolled-up state and could be easily detached from the underlying textiles. Mechanical testing of wet collagen scaffolds following detachment yielded mean values of 3.5 ± 1.9 MPa for the tensile strength, 41.0 ± 20.8 MPa for the Young's modulus and 8.1 ± 3.7% for the elongation at break. No roll-up was observed on AlO textiles without any modification, where collagen did not assemble into fibers, either. Blends of collagen and chitosan were also found to roll into fibrous constructs on silanized AlO textiles, while fibrinogen nanofibers or blends of collagen and elastin did not yield such structures. Based on these differences, we hypothesize that textile surface charge and protein charge, in combination with the porous architecture of protein nanofibers and differences in mechanical strain, are key factors in inducing a scaffold roll-up. Further studies are required to develop the observed roll-up effect into a reproducible biofabrication process that can enable the controlled production of free-standing collagen-based tubes for soft tissue engineering.
PubMed: 37601922
DOI: 10.1021/acsnanoscienceau.3c00008 -
MethodsX Dec 2023Collagen remodelling is a vital process for embryonic development and homoeostatic maintenance of the adult body. Collagen remodelling is a complex process in...
Collagen remodelling is a vital process for embryonic development and homoeostatic maintenance of the adult body. Collagen remodelling is a complex process in fibroblasts, macrophages and other cells, whereby new collagen is secreted and polymerized into fibrils and old collagen is removed by proteolysis and endocytosis. Whereas the production of collagen is well-studied, the removal of collagen is less understood. In this protocol, we describe a method for the quantification of collagen uptake by cells. This protocol is based on the polymerisation of collagen type I-FITC conjugate in cell culture plate wells. Next, unpolymerized collagen is washed away and the cells are added in cell culture media. At this stage, they can be treated with inhibitors and/or stimulants if required. Afterwards, the cells are detached from the collagen using the protease accutase and the FITC signal is quantified using microscopy and/or flow cytometry.•Easy-to-use protocol for the quantitative measurement of collagen uptake in cells.•Cell detachment from collagen is quick and easy with accutase, even with strong adhering cells like macrophages.•Downstream applications can be a wide selection of analysis techniques like microscopy, RNA- and protein isolation, and flow cytometry.
PubMed: 37533791
DOI: 10.1016/j.mex.2023.102288 -
Science (New York, N.Y.) Apr 2024The retractile type IV pilus (T4P) is important for virulence of the opportunistic human pathogen . The single-stranded RNA (ssRNA) phage PP7 binds to T4P and is brought...
The retractile type IV pilus (T4P) is important for virulence of the opportunistic human pathogen . The single-stranded RNA (ssRNA) phage PP7 binds to T4P and is brought to the cell surface through pilus retraction. Using fluorescence microscopy, we discovered that PP7 detaches T4P, which impairs cell motility and restricts the pathogen's virulence. Using cryo-electron microscopy, mutagenesis, optical trapping, and Langevin dynamics simulation, we resolved the structure of PP7, T4P, and the PP7/T4P complex and showed that T4P detachment is driven by the affinity between the phage maturation protein and its bound pilin, plus the pilus retraction force and speed, and pilus bending. Pilus detachment may be widespread among other ssRNA phages and their retractile pilus systems and offers new prospects for antibacterial prophylaxis and therapeutics.
Topics: Humans; Cryoelectron Microscopy; Fimbriae Proteins; Fimbriae, Bacterial; Pseudomonas aeruginosa; RNA Viruses; Pseudomonas Phages; Virus Internalization; Viral Proteins
PubMed: 38574145
DOI: 10.1126/science.adl0635 -
Photodiagnosis and Photodynamic Therapy Dec 2023To evaluate anterior segment parameter changes following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) using the Pentacam Scheimpflug system.
PURPOSE
To evaluate anterior segment parameter changes following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) using the Pentacam Scheimpflug system.
METHODS
Twenty-eight phakic eyes of 28 patients who underwent SB surgery for RDD were included. The anterior chamber volume (ACV), central anterior chamber depth (CACD), mean anterior chamber angle (ACA) and ACA in a specific position (buckle quadrant), and central corneal thickness (CCT) were evaluated preoperatively and at 1 day, 1 week, and 1 and 3 months postoperatively by an anterior Pentacam Scheimpflug method.
RESULTS
The ACV parameters were significantly decreased compared with preoperative levels at 1 day after SB surgery (P = 0.0004), but had no significant differences at 1 week, and 1 and 3 months (P > 0.05). The mean intraocular pressure (IOP) at 1 day was significantly higher than the preoperative level, but no subsequent significant difference was noted between the preoperative IOP and that at 1 week and 1 and 3 months postoperatively (P > 0.05). The CCT at 1 day after surgery increased significantly (P = 0.0122) and subsequently returned to the normal level postoperatively at 1 week and remained stable until 3 months (P > 0.05). The degree of postoperative ACA displayed different changes in the different quadrants and there was a significant increase in the ACA of the buckle quadrants at 1 day (P < 0.0001), 1 week (P = 0.02), and 1 month (P = 0.0266) after surgery, returning to the normal level at 3 months.
CONCLUSIONS
The changes of anterior chamber parameters after SB can be demonstrated by Pentacam both objectively and quantitatively. The ACV and CCT changes were mild and resumed their preoperative parameters after 1 week, while the increase of the ACA at the buckle quadrant returned to normal after 3 months. SB surgeries without encircling or conducted with radial buckling might decrease anterior chamber change.
Topics: Humans; Scleral Buckling; Photochemotherapy; Photosensitizing Agents; Anterior Chamber; Retinal Detachment
PubMed: 37935344
DOI: 10.1016/j.pdpdt.2023.103881 -
Trials Dec 2023Few large randomized controlled trials provide strong evidence to guide surgical repair of primary rhegmatogenous retinal detachment (RRD) repair. The purpose of this...
BACKGROUND
Few large randomized controlled trials provide strong evidence to guide surgical repair of primary rhegmatogenous retinal detachment (RRD) repair. The purpose of this factorial, single-blind, randomized controlled trial is to analyze and compare the surgical outcomes, functional visual outcomes, complications, and quality of life associated with RRD repair using (A) pars plana vitrectomy only (PPV) or PPV with scleral buckle (PPV-SB) and (B) sulfur hexafluoride gas (SF) or perfluoropropane gas (CF) tamponade.
METHODS
Eligible patients with moderately complex RRD will be randomized 1:1 to PPV or PPV-SB and 1:1 to SF or CF gas tamponade. Approximately 560 patients will be recruited to be able to detect a difference of around 10% in SSAS rate between the groups. Patients will be followed using multimodal imaging and quality of life questionnaires after the surgical repair until 1 year postoperative. The primary outcome will be a single-surgery anatomic success (SSAS), defined as the absence of reoperation for recurrent RRD in the operating room. Secondary outcomes will be pinhole visual acuity (PHVA) at 8-10 weeks and 6 months, final best-corrected visual acuity (BCVA), final retina status (i.e., attached or detached), time to onset of RRD recurrence, severity and number of complications, and questionnaire results.
DISCUSSION
This will be the first 2 × 2 factorial RCT examining repair techniques in primary RRD. It will also be the first RCT to compare gas tamponade between the two most common agents. Notably, it will be adequately powered to detect a clinically significant effect size. The use of multimodal imaging will also be a novel aspect of this study, allowing us to compare head-to-head the impact of adding an SB to the retina's recovery after RRD repair and of differing gas tamponades. Until now, the treatment of RRD has been largely guided by pragmatic retrospective cohort studies. There is a lack of strong evidence guiding therapeutic decisions and this trial will address (1) whether supplemental SB is justified and (2) whether longer duration gas tamponade with CF is necessary.
TRIAL REGISTRATION
ClinicalTrials.gov NCT05863312. Registered on 18 May 2023.
Topics: Humans; Retinal Detachment; Retrospective Studies; Quality of Life; Single-Blind Method; Treatment Outcome; Visual Acuity; Vitrectomy; Randomized Controlled Trials as Topic
PubMed: 38124155
DOI: 10.1186/s13063-023-07815-x -
Oman Journal of Ophthalmology 2023
PubMed: 38059090
DOI: 10.4103/ojo.ojo_247_22 -
Hypertension Research : Official... Dec 2023Congestive heart failure produces fluid volume overload, central and renal venous pressure elevation, and consequently renal congestion, which results in worsening renal...
Congestive heart failure produces fluid volume overload, central and renal venous pressure elevation, and consequently renal congestion, which results in worsening renal function. Pericyte detachment and pericyte-myofibroblast transition (PMT) were linked to renal interstitial fibrosis. Dahl salt-sensitive hypertensive (DahlS) rats are a non-surgical renal congestion model. The relation, however, between renal interstitial damage, pericyte morphology, and PMT in the renal congestion of DahlS rats has not been reported. DahlS rats (8-week-old) were fed normal salt (NS, 0.4% NaCl) or high salt (HS, 4% NaCl), and the left kidney was decapsulated to reduce renal interstitial hydrostatic pressure (RIHP) at 9 weeks old. One week after capsulotomy, both kidneys were analyzed by molecular and histological techniques. Renal pericyte structure was assessed in the body donors with/without venous stasis. Markers of tubulointerstitial damage, interstitial fibrosis, and PMT were upregulated in the right non-decapsulated kidney of DahlS rats fed HS. Renal tubular injury and fibrosis were detected in the HS diet groups in histological analysis. Pericyte detachment was observed in the right non-decapsulated kidney of DahlS rats fed HS by low vacuum-scanning electron microscopy. Decapsulation in DahlS rats fed HS attenuated these findings. Also, renal pericytes detached from the vascular wall in patients with heart failure. These results suggest that pericyte detachment and PMT induced by increased RIHP are responsible for tubulointerstitial injury and fibrosis in DahlS rats and humans with renal congestion. Renal venous congestion and subsequent physiological changes could be therapeutic targets for renal damage in cardiorenal syndrome.
Topics: Humans; Rats; Animals; Rats, Inbred Dahl; Pericytes; Sodium Chloride; Kidney; Hypertension; Heart Failure; Sodium Chloride, Dietary; Fibrosis; Blood Pressure
PubMed: 37845397
DOI: 10.1038/s41440-023-01451-3 -
Drug Design, Development and Therapy 2023The intestine, often referred to as the "second brain" of the human body, houses a vast microbial community that plays a crucial role in maintaining the host's balance... (Review)
Review
The intestine, often referred to as the "second brain" of the human body, houses a vast microbial community that plays a crucial role in maintaining the host's balance and directly impacting overall health. Probiotics, a type of beneficial microorganism, offer various health benefits when consumed. However, probiotics face challenges such as acidic conditions in the stomach, bile acids, enzymes, and other adverse factors before they can colonize the intestinal tissues. At present, pills, dry powder, encapsulation, chemically modified bacteria, and genetically engineered bacteria have emerged as the preferred method for the stable and targeted delivery of probiotics. In particular, the use of nanoshells on the surface of single probiotics has shown promise in regulating their growth and differentiation. These nanoshells can detach from the probiotics' surface upon reaching the intestine, facilitating direct contact between the probiotics and intestinal mucosa. In this perspective, we provide an overview of the current developments in the formation of nanoshells mediated by single probiotics. We also discuss the advantages and disadvantages of different nanocoating strategies and explore future trends in probiotic protection.
Topics: Humans; Nanoshells; Bile Acids and Salts; Brain Neoplasms; Genetic Engineering; Probiotics
PubMed: 37705759
DOI: 10.2147/DDDT.S419897 -
Ear, Nose, & Throat Journal Feb 2024Vocal fold process avulsion results from trauma that detaches the vocal process and thyroarytenoid muscle from the body of the arytenoid cartilage. Vocal fold laxity...
Vocal fold process avulsion results from trauma that detaches the vocal process and thyroarytenoid muscle from the body of the arytenoid cartilage. Vocal fold laxity often causes severe dysphonia. Findings can be subtle. A high index of suspicion often permits diagnosis and effective surgical repair.
PubMed: 38323380
DOI: 10.1177/01455613241226860 -
The American Journal of Pathology Nov 2023Retinal detachment (RD) refers to the separation between the neuroepithelium and the pigment epithelium layer. It is an important disease leading to irreversible vision...
Retinal detachment (RD) refers to the separation between the neuroepithelium and the pigment epithelium layer. It is an important disease leading to irreversible vision damage worldwide, in which photoreceptor cell death plays a major role. α-Synuclein (α-syn) is reportedly involved in numerous mechanisms of neurodegenerative diseases, but the association with photoreceptor damage in RD has not been studied. In this study, elevated transcription levels of α-syn and parthanatos proteins were observed in the vitreous of patients with RD. The expression of α-syn- and parthanatos-related proteins was increased in experimental rat RD, and was involved in the mechanism of photoreceptor damage, which was related to the decreased expression of miR-7a-5p (miR-7). Interestingly, subretinal injection of miR-7 mimic in rats with RD inhibited the expression of retinal α-syn and down-regulated the parthanatos pathway, thereby protecting retinal structure and function. In addition, interference with α-syn in 661W cells decreased the expression of parthanatos death pathway in oxygen and glucose deprivation model. In conclusion, this study demonstrates the presence of parthanatos-related proteins in patients with RD and the role of the miR-7/α-syn/parthanatos pathway in photoreceptor damage in RD.
Topics: Rats; Humans; Animals; Retinal Detachment; Apoptosis; Photoreceptor Cells, Vertebrate; alpha-Synuclein; Parthanatos; Photoreceptor Cells; MicroRNAs; Disease Models, Animal
PubMed: 37423550
DOI: 10.1016/j.ajpath.2023.06.011