ABSTRACT
The increasing emergence of infectious diseases like COVID-19 has created an urgent need for filtration/purification materials coupled with multifunctional features such as mechanical integrity, excellent airflow/filtration, and antibacterial/antimicrobial properties. Polymer membranes and metal-organic frameworks (MOFs) have demonstrated high effectiveness in air filtration and purification. MOF nanoparticles have been introduced into electrospun polymer nanofibrous membranes through embedding or postsolution growth. However, the derived hybrids are still facing the issue of (1) limited MOF exposure, which leads to low efficacy;and (2) uncontrollable growth, which leads to pore blocking and low breathability. In this work, we customized an electrospray-on-electrospinning in situ process to dynamically integrate MOF nanoparticles into a robust and elastic continuous nanofibrous membrane for advanced properties including high mechanical strength and flexibility, excellent breathability, particle filtration, and good antimicrobial performance. Biodegradable polylactic acid was reinforced by the poly(hydroxybutyrate)-di-poly(DLA-CL)x copolymer (PHBR) and used as an electrospinning matrix, while MOF nanoparticles were simultaneously electrically sprayed onto the nanofibers with easily controllable MOF loading. The MOF nanoparticles were homogeneously deposited onto nanofibers without clogging the pores in the membrane. The collision of PLA and MOF under the wet status during electrospinning and the hydrogen bonding through C=O and N-H bonds strengthen the affinity between PLA nanofibers and MOF nanoparticles. Because of these factors, the MOF-incorporated PLA/PHBR nanofibrous membrane achieved over 95% particle filtration efficiency with enhanced mechanical properties while maintaining high breathability. Meanwhile, it exhibits excellent photocatalytic antibacterial performance, which is necessary to kill microbes. The electrospray-on-electrospinning in situ process provides an efficient and straightforward way to hybridize one-dimensional (1D) or two-dimensional (2D) nanomaterials into a continuous nanofibrous membrane with strong interaction and controllable loading. Upon integrating proper functionalities from the materials, the obtained hybrids are able to achieve multifunctionalities for various applications.
ABSTRACT
The increasing emergence of infectious diseases like COVID-19 has created an urgent need for filtration/purification materials coupled with multifunctional features such as mechanical integrity, excellent airflow/filtration, and antibacterial/antimicrobial properties. Polymer membranes and metal-organic frameworks (MOFs) have demonstrated high effectiveness in air filtration and purification. MOF nanoparticles have been introduced into electrospun polymer nanofibrous membranes through embedding or postsolution growth. However, the derived hybrids are still facing the issue of (1) limited MOF exposure, which leads to low efficacy;and (2) uncontrollable growth, which leads to pore blocking and low breathability. In this work, we customized an electrospray-on-electrospinning in situ process to dynamically integrate MOF nanoparticles into a robust and elastic continuous nanofibrous membrane for advanced properties including high mechanical strength and flexibility, excellent breathability, particle filtration, and good antimicrobial performance. Biodegradable polylactic acid was reinforced by the poly(hydroxybutyrate)-di-poly(DLA-CL)x copolymer (PHBR) and used as an electrospinning matrix, while MOF nanoparticles were simultaneously electrically sprayed onto the nanofibers with easily controllable MOF loading. The MOF nanoparticles were homogeneously deposited onto nanofibers without clogging the pores in the membrane. The collision of PLA and MOF under the wet status during electrospinning and the hydrogen bonding through C═O and N-H bonds strengthen the affinity between PLA nanofibers and MOF nanoparticles. Because of these factors, the MOF-incorporated PLA/PHBR nanofibrous membrane achieved over 95% particle filtration efficiency with enhanced mechanical properties while maintaining high breathability. Meanwhile, it exhibits excellent photocatalytic antibacterial performance, which is necessary to kill microbes. The electrospray-on-electrospinning in situ process provides an efficient and straightforward way to hybridize one-dimensional (1D) or two-dimensional (2D) nanomaterials into a continuous nanofibrous membrane with strong interaction and controllable loading. Upon integrating proper functionalities from the materials, the obtained hybrids are able to achieve multifunctionalities for various applications. © 2023 American Chemical Society.
ABSTRACT
Purpose: Adverse events of a novel mRNA vaccine are not well described in Kidney Transplant Recipients(KTR), especially the risk of immune activation or recurrent glomerulonephritis(GN), which has been described in native GN after COVID-19 vaccines. Method(s): In this single-center prospective study, 147 KTR were enrolled after informed consent and administered 2 doses of Pfizer/BioNTech vaccine 21 days apart. Follow-up was 3 weeks after Dose2. Result(s): Mean age of KTR was 51 years;55.1% male;65.3% Chinese, 19% Malay, 11.6% Indian;69.5% Living donor, 29.9% Deceased donor, 0.7% Pancreas-kidney transplants;71.5% had biopsy-proven or presumptive chronic GN(CGN), 12.9% diabetic nephropathy, 15.6% other causes. 11(7.5%) KTR had delayed Dose2 administered at median 29 days(range 24-93) after Dose1. 7(4.8%)were delayed due to renal events: rise in creatinine(n=3), or proteinuria(n=2), or both creatinine and proteinuria with allograft biopsy showing acute T-cell and antibody-mediated rejection(n=1), new BK viraemia(n=1). Other reasons were possible anaphylaxis(n=1), intercurrent infection(n=2), and inability to attend due to quarantine(n=1). 27 KTR had new microhaematuria(MH) after Dose1;9 persisted after Dose2. Additional 18 had new MH after Dose2. Of 45 KTR with new MH, 7 had underlying IgAN, 5 had other biopsy-proven-CGN and 22 had presumed CGN, suggesting 34/45 with possible immune activation. 12 KTR had new onset proteinuria (rise in urine protein:creatinine ratio (UPCR) <=30 to >30mg/mmol);5/7 who developed a rise after Dose1 remained elevated;additional 5 had a rise after Dose2. 7 KTR had rise in proteinuria from UPCR <=100 to >100mg/mmol. Conclusion(s): Subclinical changes in allograft monitoring parameters are frequent after COVID-19 mRNA vaccines with up to 40.1% of KTRs showing rises in creatinine, proteinuria or new MH. Although overt recurrent GN and acute rejection are infrequent, high vigilance and monitoring for these occurrences should be undertaken in KTRs receiving mRNA vaccines.