Biosynthesis of polyhydroxyalkanoates for cardiac tissue engineering applications

As a result of the enormous clinical need, cardiac tissue engineering has become a prime focus of research within the field of tissue engineering. In this project, Poly(3- hydroxyoctanoate), P(3HO), a medium chain length (mcl-PHAs) biodegradable, biocompatible and elastomeric polyhydroxyalkanoate, was studied as a potential material for cardiac tissue engineering. Mcl-PHAs are an alternative source of polymers produced by Pseudomonas sp. As Gram-negative bacteria, Pseudomonas sp. contains lipopolysaccharides in the membrane, which are co-purified with PHAs and may cause immunogenic reactions. This limits the biomedical applications of the mcl-PHAs in several cases. In this work, the Pseudomonas mendocina PHA synthase gene (phaC1) was expressed in the LPS free, GRAS, Gram-positive microorganism, Bacillus subtilis so as to produce LPS-free mcl-PHAs. Our results showed that the recombinant Bacillus subtilis containing the phaC1 gene produced poly(3-hydroxybutirate), P(3HB), with a maximum yield of 32.3 % DCW, an unexpected result. This result thus revealed the unusually broad substrate specificity of the PHA synthase from P. mendocina, which is able to catalyse both medium and short chain length PHAs biosynthesis depending on the metabolic pool available in the host organism. Sequence comparison of this PHA synthase with stringent mcl-PHA synthases revealed possible residues influencing the substrate specificity of PHA synthases. As studies on mcl-PHAs remain limited mainly because of the lack of availability of mcl- PHAs in large quantities, the capacity to scale-up P(3HO) production from 2 L to 20 L and 72 L pilot plant bioreactors, based on constant oxygen transference, was studied. The interaction of freshly isolated rat cardiomyocytes with the P(3HO) polymer, during contraction, was studied when cells were stimulated at a range of frequencies of electrical pulses or calcium concentrations. These results showed that P(3HO) did not have any deleterious effects on the contraction of adult cardiomyocytes. P(3HO) cardiac patches nonporous, porous or with P(3HO) electrospun fibres deposited on their surface were developed. Our results showed that the mechanical properties of the final constructs were close to that of the cardiac structures, with a Young’s modulus value of 0.41±0.03 MPa. Myoblast (C2Cl2) cell proliferation was studied on the different constructs showing an enhanced cell adhesion and proliferation when both porous and fibrous structures were incorporated together. Finally, for further enhancement of the cardiac patch function, VEGF and RGD peptide were incorporated. Results obtained in this project showed that the P(3HO) multifunctional cardiac patches were potentially promising constructs for efficient cardiac tissue engineering

Hepatic venous pressure gradient predicts risk of hepatic decompensation and liver-related mortality in patients with MASLD

Background & Aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of advanced chronic liver disease (ACLD). Portal hypertension drives hepatic decompensation and is best diagnosed by hepatic venous pressure gradient (HVPG) measurement. Here, we investigate the prognostic value of HVPG in MASLD-related compensated ACLD (MASLD-cACLD). Methods: This European multicentre study included patients with MASLD-cACLD characterised by HVPG at baseline. Hepatic decompensation (variceal bleeding/ascites/hepatic encephalopathy) and liver-related mortality were considered the primary events of interest. Results: A total of 340 patients with MASLD-cACLD (56.2% male; median age 62 [55-68] years, median MELD 8 [7-9], 71.2% with diabetes) were included. Clinically significant portal hypertension (CSPH: i.e., HVPG ≥10 mmHg) was found in 209 patients (61.5%). During a median follow-up of 41.5 (27.5-65.8) months, 65 patients developed hepatic decompensation with a cumulative incidence of 10.0% after 2 years (2Y) and 30.7% after 5 years (5Y) in those with MASLD-cACLD with CSPH, compared to 2.4% after 2Y and 9.4% after 5Y in patients without CSPH. Variceal bleeding did not occur without CSPH. CSPH (subdistribution hazard ratio [SHR] 5.13; p <0.001) was associated with an increased decompensation risk and a higher HVPG remained an independent risk factor in the multivariable model (adjusted SHR per mmHg: 1.12, p <0.001). Liver-related mortality occurred in 37 patients at a cumulative incidence of 3.3% after 2Y and 21.4% after 5Y in CSPH. Without CSPH, the incidence after 5Y was 0.8%. Accordingly, a higher HVPG was also independently associated with a higher risk of liver-related death (adjusted SHR per mmHg: 1.20, p <0.001). Conclusion: HVPG measurement is of high prognostic value in MASLD-cACLD. In patients with MASLD-cACLD without CSPH, the short-term risk of decompensation is very low and liver-related mortality is rare, while the presence of CSPH substantially increases the risk of both. Impact and implications: While the incidence of compensated advanced chronic liver disease (cACLD) due to metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing worldwide, insights into the impact of clinically significant portal hypertension (CSPH) on the risk of liver-related events in MASLD-cACLD remain limited. Based on the findings of this European multicentre study including 340 MASLD-cACLD patients, we could show that increasing HVPG values and the presence of CSPH in particular were associated with a significantly higher risk of first hepatic decompensation and liver-related mortality. In contrast, the short-term incidence of decompensation in patients with MASLD-cACLD without CSPH was low and the risk of liver-mortality remained negligible. Thus, HVPG measurements can provide important prognostic information for individualised risk stratification in MASLD-cACLD and may help facilitate the study of novel and promising treatment possibilities for MASLD

Biosynthesis and characterization of a novel, biocompatible medium chain length polyhydroxyalkanoate by Pseudomonas mendocina CH50 using coconut oil as the carbon source

This study validated the utilization of triacylglycerides (TAGs) by Pseudomonas mendocina CH50, a wild type strain, resulting in the production of novel mcl-PHAs with unique physical properties. A PHA yield of 58% dcw was obtained using 20g/L of coconut oil. Chemical and structural characterisation confirmed that the mcl-PHA produced was a terpolymer comprising of three different repeating monomer units, 3-hydroxyoctanoate, 3-hydroxydecanoate and 3-hydroxydodecanoate or P(3HO-3HD-3HDD). Bearing in mind the potential of P(3HO-3HD-3HDD) in biomedical research, especially in neural tissue engineering, in vitro biocompatibility studies were carried out using NG108-15 (neuronal) cells. Cell viability data confirmed that P(3HO-3HD-3HDD) supported the attachment and proliferation of NG108-15 and was therefore, confirmed to be biocompatible in nature and suitable for neural regeneration

A streamlined pathway for transcatheter aortic valve implantation : the BENCHMARK study

Background and There is significant potential to streamline the clinical pathway for patients undergoing transcatheter aortic valve implant-Aims ation (TAVI). The purpose of this study was to evaluate the effect of implementing BENCHMARK best practices on the efficiency and safety of TAVI in 28 sites in 7 European countries. Methods This was a study of patients with severe symptomatic aortic stenosis (AS) undergoing TAVI with balloon-expandable valves before and after implementation of BENCHMARK best practices. Principal objectives were to reduce hospital length of stay (LoS) and duration of intensive care stay. Secondary objective was to document patient safety. Results Between January 2020 and March 2023, 897 patients were documented prior to and 1491 patients after the implementation of BENCHMARK practices. Patient characteristics were consistent with a known older TAVI population and only minor differences. Mean LoS was reduced from 7.7 ± 7.0 to 5.8 ± 5.6 days (median 6 vs. 4 days; P <.001). Duration of intensive care was reduced from 1.8 to 1.3 days (median 1.1 vs. 0.9 days; P <.001). Adoption of peri-procedure best practices led to increased use of local anaesthesia (96.1% vs. 84.3%; P <.001) and decreased procedure (median 47 vs. 60 min; P <.001) and intervention times (85 vs. 95 min; P <.001). Thirty-day patient safety did not appear to be compromised with no differences in all-cause mortality (0.6% in both groups combined), stroke/transient ischaemic attack (1.4%), life-threatening bleeding (1.3%), stage 2/3 acute kidney injury (0.7%), and valve-related readmission (1.2%). Conclusions Broad implementation of BENCHMARK practices contributes to improving efficiency of TAVI pathway reducing LoS and costs without compromising patient safety

A streamlined pathway for transcatheter aortic valve implantation: the BENCHMARK study

Background and Aims There is significant potential to streamline the clinical pathway for patients undergoing transcatheter aortic valve implantation (TAVI). The purpose of this study was to evaluate the effect of implementing BENCHMARK best practices on the efficiency and safety of TAVI in 28 sites in 7 European countries. Methods This was a study of patients with severe symptomatic aortic stenosis (AS) undergoing TAVI with balloon-expandable valves before and after implementation of BENCHMARK best practices. Principal objectives were to reduce hospital length of stay (LoS) and duration of intensive care stay. Secondary objective was to document patient safety. Results Between January 2020 and March 2023, 897 patients were documented prior to and 1491 patients after the implementation of BENCHMARK practices. Patient characteristics were consistent with a known older TAVI population and only minor differences. Mean LoS was reduced from 7.7 +/- 7.0 to 5.8 +/- 5.6 days (median 6 vs. 4 days; P &lt; .001). Duration of intensive care was reduced from 1.8 to 1.3 days (median 1.1 vs. 0.9 days; P &lt; .001). Adoption of peri-procedure best practices led to increased use of local anaesthesia (96.1% vs. 84.3%; P &lt; .001) and decreased procedure (median 47 vs. 60 min; P &lt; .001) and intervention times (85 vs. 95 min; P &lt; .001). Thirty-day patient safety did not appear to be compromised with no differences in all-cause mortality (0.6% in both groups combined), stroke/transient ischaemic attack (1.4%), life-threatening bleeding (1.3%), stage 2/3 acute kidney injury (0.7%), and valve-related readmission (1.2%). Conclusions Broad implementation of BENCHMARK practices contributes to improving efficiency of TAVI pathway reducing LoS and costs without compromising patient safety

PENGARUH KEPEMIMPINAN DAN DISIPLIN KERJA TERHADAP KINERJA KARYAWAN PADA PT. DISTRIBUSI SENTRA JAYA

Tujuan. Penelitian ini bertujuan untuk mengetahui adakah pengaruh atau seberapa besarkah pengaruh variabel kepemimpinan dan disiplin kerja terhadap kinerja karyawan PT. Distribusi Sentra Jaya - Tangerang Selatan.Metode. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif, dimana teknik pengumpulan data yang digunakan dengan penyebaran kuesioner. Sampel dalam penelitian ini adalah karyawan PT. Distribusi Sentra Jaya Tangerang Selatan yang berjumlah 65 orang dengan metode sampel jenuh. Metode yang digunakan adalah regresi linear berganda.Hasil. Dari hasil pengolahan data menggunakan SPSS 26 didapati bahwa Adjusted R Square sebesar 49,2%. Artinya, variabel Kepemimpinan dan Disiplin Kerja dapat menjelaskan variabel Kinerja sebesar 49,2%. Selisihnya, dipengaruhi oleh variabel lain yang tidak digunakan dalam penelitian ini. Hasil dari penelitian ini menyimpulkan bahwa secara parsial, variabel kepemimpinan dan disiplin kerja berpengaruh signifikan terhadap kinerja karyawan PT. Distribusi Sentra Jaya - Tangerang Selatan. Secara simultan, kepemimpinan dan disiplin kerja berpengaruh terhadap Kinerja karyawan.Implikasi. Perusahaan harus menumbuhkan kesadaran pada seluruh karyawan agar memiliki Tanggung jawab menyelesaiakan pekerjaan. Perusahaan harus memberikan tempat kerja yang nyaman agar karyawan bekerja ihklas