Fulminant Streptococcus suis Infection Causing Myocardial Damage and Toxic Shock-Like Syndrome: A Case Report.

There have been no prior reports of direct myocardial damage caused by Streptococcus suis (S. suis), and understanding the clinical course of myocardial involvement is crucial for early diagnosis and initiation of treatment for this infection. A male pig farmer presented as an outpatient with a fever and sore throat, but within hours, his cardiac function declined, and his general condition deteriorated. Despite receiving comprehensive treatment, he succumbed to complications associated with toxic shock-like syndrome (TSLS). Blood cultures identified S. suis, and myocardial pathology revealed the presence of this bacterium in necrotic areas. This case marks the first reported instance of myocardial damage accompanied by TSLS due to S. suis, highlighting the significance of this infection.

Peripheral intravascular lithotripsy to facilitate transfemoral transcatheter aortic valve replacement - Defining optimal treatable peripheral arterial disease burden.

BACKGROUND: Transfemoral transcatheter aortic valve replacement (TF-TAVR) has proven superior to alternative access. However, some patients evaluated for TF-TAVR are unfit secondary to peripheral arterial disease (PAD). Peripheral intravascular lithotripsy (IVL) can facilitate femoral access. This study aimed to characterize optimal lesions that can be treated with IVL. METHODS: Single-center, retrospective analysis of an institutional database, queried from 1/2018 through 7/2023 for all patients who underwent TAVR. Patients who received IVL-facilitated transfemoral access were analyzed. RESULTS: Of 2862 TAVR cases identified, 92 (3.2 %) underwent lithotripsy. The IVL-facilitated cohort had a mean age of 78 ± 9.2 years and 45 % were female. The right common iliac artery was most treated (47). Most IVL was performed with 7-mm balloons (73.9 %). All cases were successful. 30-day mortality was 1.1 % (1/92). CONCLUSIONS: In our cohort, complications after IVL-facilitated TF-TAVR were more common with small vessel diameter (≤4.7 mm), significant luminal loss (>50 % stenosis), and heavy calcium burden (arc calcification >180°). The findings support the use of IVL to expand the population of patients who can undergo TF-TAVR without the increased risks associated with the various forms of alternative access. SUMMARY FOR ANNOTATED TABLE OF CONTENTS: IVL-facilitated TF-TAVR is safe and feasible. Despite its introduction to TAVR clinical practice in 2018, IVL-facilitated TF-TAVR is not regularly performed and could increase the population of patients eligible for TF-TAVR.

Relationships among hemolysis indicators and neuron-specific-enolase in patients undergoing veno-arterial extracorporeal membrane oxygenation.

Neuron-specific-enolase is used as a marker of neurological prognosis after cardiopulmonary resuscitation. It is also present in red blood cells and platelets. It is not known whether hemolysis increases the values of neuron-specific-enolase enough to clinically affect its interpretation in critically ill patients who are to be introduced to veno-arterial extracorporeal oxygenation. In this study, we examined the relationships among neuron-specific-enolase and hemolysis indicators such as free hemoglobin and lactate dehydrogenase after the introduction of veno-arterial extracorporeal oxygenation. Of the 91 patients who underwent veno-arterial extracorporeal membrane oxygenation in our hospital from January 1, 2018, to February 24, 2021, 68 patients survived for more than 24 h. Of these, 14 patients who were categorized into the better cerebral performance categories (1-3) and 19 patients who were categorized into the poor neurological prognosis category (4) were included. After the introduction of veno-arterial extracorporeal membrane oxygenation, neuron-specific-enolase was markedly higher in the poor neurological prognosis group than in the good neurological prognosis group (41.6 vs. 92.0, p = 0.04). A significant positive correlation was revealed between neuron-specific-enolase and free hemoglobin in the good neurological prognosis group (rs = 0.643, p = 0.0131). A similar relationship was observed for lactate dehydrogenase and neuron-specific-enolase in both the conscious (rs = 0.737, p = 0.00263) and non-conscious groups (rs = 0.544, p = 0.0176). When neuron-specific-enolase is used as a marker for neuroprognostic evaluation, an abnormally high value is likely to indicate the lack of consciousness, whereas a lower elevation should be interpreted with caution, taking into account the effects of hemolysis.

Discovery of an anti-malarial compound, burnettiene A, with a multidrug-sensitive Saccharomyces cerevisiae screening system based on mitochondrial function inhibitory activity.

In this paper, we describe our discovery of burnettiene A (1) as an anti-malarial compound from the culture broth of Lecanicillium primulinum (Current name: Flavocillium primulinum) FKI-6715 strain utilizing our original multidrug-sensitive yeast system. This polyene-decalin polyketide natural product was originally isolated as an anti-fungal active compound from Aspergillus burnettii. However, the anti-fungal activity of 1 has been revealed in only one fungal species for and the mechanism of action of 1 remains unknown. After the validation of mitochondrial function inhibitory of 1, we envisioned a new anti-malarial drug discovery platform based on mitochondrial function inhibitory activity. We evaluated anti-malarial activity and 1 showed anti-malarial activity against Plasmodium falciparum FCR3 (chloroquine sensitive) and K1 strain (chloroquine resistant). Our study revealed the utility of our original screening system based on a multidrug-sensitive yeast and mitochondrial function inhibitory activity for the discovery of new anti-malarial drug candidates.

Mitral regurgitation increases systolic strains in remote zone and worsens left ventricular dyssynchrony in a swine model of ischemic cardiomyopathy.

Background: Ischemic mitral regurgitation (IMR) imposes volume overload on the left ventricle (LV), accelerating adverse LV remodeling. In this study, we sought to investigate the impact of volume overload due to IMR on regional myocardial contractile mechanics. Methods: Ten Yorkshire swine were induced with myocardial infarction (MI) by occluding the left circumflex coronary artery (LCx). Cardiac MRI was performed at baseline (BL) and 2.5 months (2.5M) post-MI. IMR was quantified with epicardial echocardiography 3 months post-MI. The animals were then assigned to 2 groups: no/mild MR (nmMR, n = 4) and moderate/severe MR (msMR, n = 6). MRI images were analyzed to assess infarction size, end-diastolic and end-systolic volume (EDV and ESV, respectively), ejection fraction (EF), longitudinal strain (LS), circumferential strain (CS), and systolic dyssynchrony index (SDI). The myocardial region was divided into infarction, border, and remote zones based on the LCx-supplied region. Results: There was no difference in the infarction size. Group-wise comparison of LS and CS between BL and 2.5M demonstrated that LS and CS in the infarction zone and the border zone decreased at 2.5M in both groups. However, LS and CS in the remote zone were elevated only in the msMR group (LS: -9.81 ± 3.96 vs. -12.58 ± 5.07, p < 0.01; CS; -12.78 ± 3.81 vs. -16.09 ± 3.33, p < 0.01) at 2.5M compared to BL. The SDI of CS was significantly elevated in the msMR group (0.1255 vs. 0.0974, p = 0.015) at 2.5M compared to BL. Conclusions: Elevated LS and CS in the remote zone were observed in moderate/severe MR and ventricular dyssynchrony. These elevated cardiac strains, coupled with ventricular dyssynchrony, may contribute to the progression of MR, thereby accelerating heart failure.

Relationship between prehabilitation responsiveness and postoperative physical functional recovery in cardiovascular surgery.

BACKGROUND: The purpose of this study was to examine the relationship between responsiveness to prehabilitation and postoperative recovery of physical function in cardiac surgery patients. METHODS: Ninety-three cardiac surgery patients (mean age: 76.4 years) were included in this retrospective cohort study. Preoperative physical function was measured using the Short Physical Performance Battery (SPPB), and a prehabilitation exercise program was implemented for the SPPB domains with low scores. Among the patients, those whose SPPB score was over 11 from the start of prehabilitation and remained over 11 on the day before surgery were defined as the high-functioning group, and those whose SPPB score improved by 2 points or more from the start of prehabilitation and exceeded 11 points were defined as the responder group. Those whose SPPB score did not exceed 11 immediately before surgery were classified as non-responders. The characteristics of each group and postoperative recovery of physical function were investigated. RESULTS: There were no serious adverse events during prehabilitation. Mean days of prehabilitation was 5.4 days. The responder group showed faster improvement in postoperative physical function and shorter time to ambulatory independence than the non-responder group. The non-responder group had lower preoperative skeletal muscle index, more severe preoperative New York Heart Association classification, and a history of musculoskeletal disease or stroke. CONCLUSION: There were responders and non-responders to prehabilitation among cardiac surgery patients. Cardiac surgery patients who respond to prehabilitation had faster recovery of physical function. Further research is needed to determine what type of prehabilitation is more effective in postoperative recovery of physical function in cardiac surgery patients.

Current status of the surgical training system in Japan: results of a nationwide questionnaire survey of graduating surgical trainees.

PURPOSE: To identify the problems trainees face during surgical training in Japan. METHODS: A nationwide online questionnaire survey was conducted targeting newly certified surgical trainees. RESULTS: The response rate was 53.8% (758/1410). Among those respondents, 25.6% were women, 71.4% were either married or had a partner, 41.3% had children, 72.7% had performed over 200 surgeries under general anesthesia, and 54.1% had chosen, before graduating from medical school, to become a surgeon. While 88.8% were interested in learning surgical techniques, 63.8% were hesitant to become a surgeon for fear of a compromised quality of private life (QOL). Conversely, only 1.4% chose their surgical training programs based on QOL. Overall, 84.6% of the trainees were satisfied with their training and this correlated with the number of surgeries performed. Only 29.9% received non-technical skill training. The average number of night shifts per month was 5.6, and 10.6% worked over 80 h per week. Harassment was reported by 41.5% of the respondents. Moreover, 33.0% had considered dropping out at some time, primarily because of their QOL (51.1%) or the harassment they had encountered (50.4%). CONCLUSION: This survey revealed that while trainees were satisfied with the overall training system, issues such as long working hours and harassment are prevalent. Working to improve these issues could make surgery more attractive for young trainees.

Correlation between the spread of IMP-producing bacteria and the promoter strength of blaIMP genes.

The first report of transmissible carbapenem resistance encoded by blaIMP-1 was discovered in Pseudomonas aeruginosa GN17203 in 1988, and blaIMP-1 has since been detected in other bacteria, including Enterobacterales. Currently, many variants of blaIMPs exist, and point mutations in the blaIMP promoter have been shown to alter promoter strength. For example, the promoter (Pc) of blaIMP-1, first reported in P. aeruginosa GN17203, was a weak promoter (PcW) with low-level expression intensity. This study investigates whether point mutations in the promoter region have helped to create strong promoters under antimicrobial selection pressure. Using bioinformatic approaches, we retrieved 115 blaIMPs from 14,529 genome data of Pseudomonadota and performed multiple alignment analyses. The results of promoter analysis of the 115 retrieved blaIMPs showed that most of them used the Pc located in class 1 integrons (n = 112, 97.4%). The promoter analysis by year revealed that the blaIMP population with the strong promoter, PcS, was transient. In contrast, the PcW-TG population, which had acquired a TGn-extended -10 motif in PcW and had an intermediate promoter strength, gradually spread throughout the world. An inverse correlation between Pc promoter strength and Intl1 integrase excision efficiency has been reported previously [1]. Because of this trade-off, it is unlikely that blaIMPs with strong promoters will increase rapidly, but the possibility that promoter strength will increase with the use of other integrons cannot be ruled out. Monitoring of the blaIMP genes, including promoter analysis, is necessary for global surveillance of carbapenem-resistant bacteria.

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001.

Actinomycetes are well-known as the main producers of bioactive compounds such as antibiotics, anticancers, and immunosuppressants. Screening of natural products from actinomycetes has been an essential part of several drug discovery programs. Finding such novel biologically active metabolites is immensely important because of their beneficial health effects. Recently, the discovery of new compounds has diverted attention to rare actinomycetes, since they are rich sources of natural products. In this study, a collection of rare actinomycetes at Kitasato University has been screened for potential novel compound producers. Among the rare actinomycetes, Saccharopolyspora sp. KR21-0001 isolated from soil on Oha Island, Okinawa, Japan was selected as a potential producer. The strain was cultured in 20 L of production medium in a jar fermenter and the culture broth was extracted. Further purification revealed the presence of a new compound designated KR21-0001A (1). The structure was elucidated by NMR, and the absolute stereochemistry was determined by advanced Marfey's method. The results indicated that 1 is a new analog of dihydroxybenzoic acid. 1 has no antimicrobial activity against bacteria and fungi but showed potent antioxidant activity.

Akedanones A-C, In Vitro and In Vivo Antiplasmodial 2,3-Dihydronaphthoquinones Produced by Streptomyces sp. K20-0187.

Three new antiplasmodial compounds, named akedanones A (1), B (2), and C (3), were discovered from the cultured material of Streptomyces sp. K20-0187 isolated from a soil sample collected at Takeda, Kofu, Yamanashi prefecture in Japan. The structures of compounds 1-3 were elucidated as new 2,3-dihydronaphthoquinones having prenyl and reverse prenyl groups by mass spectrometry and nuclear magnetic resonance analyses. Compound 1 and the known furanonaphthoquinone I (4) showed potent in vitro antiplasmodial activity against chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains, with half-maximal inhibitory concentration values ranging from 0.06 to 0.3 µM. Compounds 1 and 4 also displayed potent in vivo antiplasmodial activity against drug-sensitive rodent malaria Plasmodium berghei N strain, with inhibition rates of 47.6 and 43.1%, respectively, on intraperitoneal administration at a dose of 5 mg kg-1 day-1 for 4 days.

Bail-Out TEVAR through a Branch of Four-Arm Dacron Graft for Misdeployment of a Frozen Elephant Trunk Prosthesis.

The frozen elephant trunk (FET) is an effective method for making the distal anastomosis more proximal and facilitating aortic remodeling in acute aortic dissection. However, misdeployment of FET to the false lumen has been reported in several cases. Such cases are usually treated with bail-out thoracic endovascular aortic repair (TEVAR) through the femoral artery or additional FET under direct vision to redirect the blood flow to the true lumen. We encountered a case of misdeployment of FET into the false lumen during open aortic surgery for the treatment of Stanford type A acute aortic dissection. After reconstruction of the aorta and all arch vessels, we performed antegrade bail-out TEVAR through a side branch of the four-arm Dacron graft as main access using a pull-through technique through the right femoral artery, which was perfused from the true lumen. This technique, which uses a Dacron graft branch for stent graft access, enabled us to confirm the true lumen because the distal anastomotic site was definitely the true lumen, and we were also able to avoid access difficulties at the iliac artery.

Impella Implantation as a Bridge to Surgery for Repair of Aorto-Right Ventricular Fistula Following Prosthetic Valve Endocarditis: A Case Report.

For patients with cardiogenic shock, delaying surgery with mechanical circulatory support is reported to yield better outcomes than emergency surgery. We report on an 82-year-old man diagnosed with vertebral osteomyelitis with concomitant infective endocarditis. Chest radiographs revealed a growing abscess, which resulted in an aorto-right ventricular fistula. Providing Impella support allowed for hemodynamic stabilization prior to surgery. The patient had an uneventful postoperative course and reported to be well in a follow-up 1 year later. Impella support can be used as a bridge to surgery for repairing fistulous tract formation in patients in cardiogenic shock.

Transapical ventricular reshaping reduces functional mitral regurgitation and improves ventricular function in a preclinical model of ischemic cardiomyopathy.

OBJECTIVE: A significant proportion of patients with advanced heart failure present with dilated left ventricles and functional mitral regurgitation. These patients currently have limited treatment options. The MitraClip device (Abbott) has benefited only patients with smaller left ventricles (end-diastolic dimension <70 mm), whereas those with larger left ventricles did not benefit. A possible explanation is correcting functional mitral regurgitation alone may not adequately reduce the wall stresses of a dilated left ventricle. We have developed a beating-heart device that not only approximates the papillary muscles to reduce functional mitral regurgitation but also modifies the left ventricle size and shape to reduce wall stress. METHODS: Yorkshire swine (n = 16) had a myocardial infarction induced by permanent occlusion of the left circumflex with intracoronary ethanol. Three months later, the animals developed heart failure and moderate or greater functional mitral regurgitation. Through a transapical approach, the new device was implanted under echocardiography guidance to reshape the left ventricle and correct functional mitral regurgitation. The acute impact of this approach on the mitral valve and left ventricle was assessed with echocardiography and invasive hemodynamics. RESULTS: After reshaping, echocardiography showed a decrease in end-diastolic volume by 36.3 ± 30.5 mL (P < .001), a decrease in sphericity index by 0.143 ± 0.087 (P < .001), and an increase in ejection fraction of 5.90% ± 6.38% (P < .01). Mitral valve tenting area was reduced by 39.29 ± 33.66 mm2 (P < .001), coaptation length was increased by 2.12 ± 1.02 mm (P < .001), and posterior excursion angle was improved by 9.07° ± 9.14° (P < .01), resulting in functional mitral regurgitation reduction. CONCLUSIONS: Correction of functional mitral regurgitation with favorable changes in mitral valve geometry and reduction in left ventricle geometry is possible with the proposed device.

Emblestatin: a new peptide antibiotic from Embleya scabrispora K20-0267.

A new peptide, emblestatin (1), was discovered from a culture broth of Embleya scabrispora K20-0267. This strain was isolated from soil using an agar medium containing lysozyme. Based on NMR and mass spectrometric analyses, 1 consists of 2-(2-hydroxyphenyl)-2-oxazoline, ß-alanine, glutamine, Nα-methyl-Nω-hydroxyornithine and 3-amino-1-hydroxy-2-piperidone moieties. Further analysis using the advanced Marfey's method revealed that all amino acids with the stereogenic α-carbon in 1 had the L configuration. Compound 1 exhibited iron chelating activity and weak antibacterial activity against Proteus vulgaris and Staphylococcus aureus.

Comprehensive analysis of biosynthetic gene clusters in bacteria and discovery of Tumebacillus as a potential producer of natural products.

Limited microbial genera such as Streptomyces have served as sources of natural products (NPs), whereas most others have been less investigated. The vast accumulation of genomic data available in the NCBI database enables us to bioinformatically estimate the ability of other microbial groups to produce NPs. We analyzed 21,052 complete bacterial genome sequences using antiSMASH and compared the average numbers of biosynthetic gene clusters (BGCs) related to polyketides, non-ribosomal peptides, and/or terpenes biosynthesis at the genus level. Our bioinformatic analyses showed that Tumebacillus has 5-15 BGCs and is a promising NP producer. We searched for NPs from the culture broth of Tumebacillus permanentifrigoris JCM 14557T and found two novel compounds (tumebacin with anti-Bacillus activity and tumepyrazine) and identified two known compounds. Our results highlight the diversity of sources of NPs awaiting discovery.

Proximal and extended aortic arch replacement in acute DeBakey type I aortic dissection.

Objective: This study aimed to compare the short- and long-term outcomes of proximal repair vs. extensive arch surgery for acute DeBakey type I aortic dissection. Subjects: From April 2014 to September 2020, 121 consecutive patients with acute type A dissection were surgically treated at our institute. Of these patients, 92 had dissections extending beyond the ascending aorta. Methods: Of the 92 patients, 58 underwent proximal repair, including aortic root and/or hemiarch replacement, and 34 underwent extended repair, including partial and total arch replacement. Perioperative variables and early and late postoperative results were statistically analyzed. Results: The duration of surgery, cardiopulmonary bypass, and circulatory arrest was significantly shorter in the proximal repair group (p < 0.01). The overall operative mortality rate was 10.3% in the proximal repair group and 14.7% in the extended repair group (p = 0.379). The mean follow-up period was 31.1 ± 26.7 months in the proximal repair group and 35.3 ± 26.8 months in the extended repair group. During follow-up, the cumulative survival and freedom from reintervention rates at 5 years were 66.4% and 92.9% in the proximal repair group, and 76.1% and 72.6% in the extended repair group, respectively (p = 0.515 and p = 0.134). Conclusions: No significant differences were found in the rates of long-term cumulative survival and freedom from aortic reintervention between the two surgical strategies. These findings suggest limited aortic resection achieves acceptable patient outcomes.

Mesenteric Ischemia After Cardiac Surgery in Dialysis Patients: An Overlooked Risk Factor.

BACKGROUND: No study has examined the association of the calcification of abdominal artery orifices with nonocclusive mesenteric ischemia (NOMI) in dialysis patients undergoing cardiac surgery. Thus, this study aimed to determine whether calcification of abdominal blood vessel orifices in hemodialysis patients may be a risk factor for NOMI and examine the long-term survival of dialysis patients after undergoing cardiac surgery. METHODS: From April 2014 to September 2020, 100 dialysis patients underwent cardiac surgery at our hospital. The calcification of the celiac artery (CA) and superior mesenteric artery (SMA) was evaluated by computed tomography, and the degree of orifice stenosis was graded as follows: patent, 0; partial occlusion, 1; and complete occlusion, 2. RESULTS: Eight patients experienced NOMI, and all of them died. SMA calcification scores were not significantly different between the NOMI and non-NOMI groups (1.38±0.52 vs. 1.13±0.69; P = 0.247). However, the average CA orifice calcification score was significantly greater in the NOMI group than in the non-NOMI group (1.63±0.52 vs. 1.15±0.65; P = 0.039), and the SMA+CA orifice calcification scores were significantly different between the groups (3.00±0.76 vs. [non-NOMI] 2.25±1.18; P = 0.028). In all patients, the 30-day and in-hospital mortality rates were 13% and 18%, respectively. All patients were completely followed up with a mean follow-up period of 604±585 days. Kaplan-Meier survival curves showed that patients with SMA and CA calcification tended to have a shorter overall survival than patients without calcification; however, no significant difference was noted. CONCLUSIONS: The calcification of CA and/or SMA orifices was associated with postoperative NOMI and poor long-term survival among dialysis patients undergoing cardiac surgery.

Similarities between Disaster Food and Space Food.

Disaster and space environments are similar in that they are closed environment, with limited lifelines. Here, we examined the similarity between disaster food and space food, to explore interactive problem-solving of food support for disaster and space environments. The Japan Disaster Food Certification Standards (Japan Disaster Food Society) and the Japanese Space Food Certification Standards (Japan Aerospace Exploration Agency) requirements and certified products, which were posted on the websites as of June 16, 2021, were compared. Certified products were classified into "staple foods," "main and/or side dishes," "milk and dairy products," "fruits," "confectionery and favorite beverages," "condiments," "dietary supplements," and "sets." Certification standards involved six items for Japan Disaster Food and eight items for Japanese Space Food. Most standards were similar. Concretely, both standards demanded room temperature storage, tough packaging and hygiene management in facilities. Both emphasized habitual food and easy eating. However, the best-by date was ≥6 mo for Japan Disaster Food, but ≥1.5 y for Japanese Space Food. In addition, Japanese Space Food required noted nutritious, food hygienic, eatable in space, cookable by specific equipment, endurable pressure by launch, and domestically produced food. There were 171 and 47 products of Japan Disaster Food and Japanese Space Food, respectively. Staple foods (pregelatinized rice, etc.) and main and/or side dishes were commonest among Japan Disaster Foods and Japanese Space Foods, respectively. It is possible to utilize of Space Food as Disaster Food, but there are some issues that must be cleared before "utilization of Disaster Food as Space Food."

Modified turn-up technique for proximal anastomosis in acute aortic dissection type A has potential to facilitate stable outcomes for low-volume early-career surgeons.

Objective: Secure proximal anastomosis is an essential part of surgical treatment for acute aortic dissection type A (AADA). This study aimed to investigate the effectiveness of the modified turn-up technique for proximal anastomosis in AADA and compare this technique with other techniques. Methods: We divided 57 patients who underwent ascending aorta replacement for AADA into the modified turn-up technique group (group A: 36 patients) and the other technique group (group B: 21 patients). Intraoperative and postoperative course data were compared between groups A and B. In group A, we also compared early-career surgeons (practicing for <10 years after graduation) and aged surgeons (practicing for ≥10 years after graduation). Results: Preoperative patient characteristics did not differ between groups. There was a tendency toward shorter operation time in group A than in group B without statistical significance (p = 0.12), and the length of intensive care unit stay was significantly shorter (p < 0.01); the occurrence of cerebral infarction was lower (p < 0.01) in group A than in group B, whereas mortality and major complications other than the cerebral infarction rate did not differ between the groups. In group A, 13 patients were operated on by early-career surgeons, while 23 patients were operated on by surgeons with more than 10 years of experience. Aortic clamp time and circulatory arrest time were significantly longer in patients operated on by early-career surgeons, but outcomes were comparable. Conclusions: The modified turn-up technique was comparable to other techniques. Even for less skilled surgeons (e.g., early-career surgeons), the use of this technique may lead to stable outcomes.

Polyvinyl alcohol coating prevents platelet adsorption and improves mechanical property of polycaprolactone-based small-caliber vascular graft.

The low patency of synthetic vascular grafts hinders their practical applicability. Polyvinyl alcohol (PVA) is a non-toxic, highly hydrophilic polymer; thus, we created a PVA-coated polycaprolactone (PCL) nanofiber vascular graft (PVA-PCL graft). In this study, we examine whether PVA could improve the hydrophilicity of PCL grafts and evaluate its in vivo performance using a rat aorta implantation model. A PCL graft with an inner diameter of 1 mm is created using electrospinning (control). The PCL nanofibers are coated with PVA, resulting in a PVA-PCL graft. Mechanical property tests demonstrate that the PVA coating significantly increases the stiffness and resilience of the PCL graft. The PVA-PCL surface exhibits a much smaller sessile drop contact angle when compared with that of the control, indicating that the PVA coating has hydrophilic properties. Additionally, the PVA-PCL graft shows significantly less platelet adsorption than the control. The proposed PVA-PCL graft is implanted into the rat's abdominal aorta, and its in vivo performance is tested at 8 weeks. The patency rate is 83.3% (10/12). The histological analysis demonstrates autologous cell engraftment on and inside the scaffold, as well as CD31/α-smooth muscle positive neointima regeneration on the graft lumen. Thus, the PVA-PCL grafts exhibit biocompatibility in the rat model, which suggests that the PVA coating is a promising approach for functionalizing PCL.