High-Yielding Nanobelt Formation by Chirality-Assisted Synthesis.

Shape-persistent Conjugated nanobelts are fascinating synthetic targets. However, in most cases these are made in low overall yields by applying strategies of macrocyclization followed by (multiple) ring fusion reactions for nanobelt formation. Here, we describe the high yielding synthesis of enantiopure chiral nanobelts in 84% yield by applying chirality-assisted synthesis (CAS). The chiral nanobelts were investigated by UV/vis and CD spectroscopy. By DFT calculations the aromaticity of these structures is discussed.

Exploring the effects of 4-chloro-o-phenylenediamine on human fibrinogen: A comprehensive investigation via biochemical, biophysical and computational approaches.

Fibrinogen (Fg), an essential plasma glycoprotein involved in the coagulation cascade, undergoes structural alterations upon exposure to various chemicals, impacting its functionality and contributing to pathological conditions. This research article explored the effects of 4-Chloro-o-phenylenediamine (4-Cl-o-PD), a common hair dye component (IUPAC = 1-Chloro-3,4-diaminobenzene), on human fibrinogen through comprehensive computational, biophysical, and biochemical approaches. The formation of a stable ligand-protein complex is confirmed through molecular docking and molecular dynamics simulations, revealing possible interaction having a favorable -4.8 kcal/mol binding energy. Biophysical results, including UV-vis and fluorescence spectroscopies, corroborated with the computational findings, whereas Fourier transform infrared spectroscopy (FT-IR) and circular dichroism spectroscopy (CD) provide insights into the alterations of secondary structures upon interaction with 4-Cl-o-PD. Anilinonaphthalene-sulfonic acid (ANS) fluorescence showed a partially unfolded protein, with enhanced α to ß-sheet transition as evidenced by thioflavin T (ThT) spectroscopy and microscopy. Moreover, biochemical assays confirmed the formation of carbonyl compounds that may be responsible for the oxidation of methionine residues in fibrinogen. Electrophoresis and electron microscopy confirmed the formation of aggregates. Our findings elucidate the interaction pattern of 4-Cl-o-PD with Fg, leading to structural perturbation, which may have potential implications for fibrinogen misfolding or its aggregation. Protein aggregation or its misfolded products affect peripheral tissues and the central nervous system. Many chronic progressive diseases, like type II diabetes mellitus, Alzheimer's disease, Parkison's disease, and Creutzfeldt-Jakob disease are associated with intrinsically aberrant disordered proteins. Understanding these interactions may offer new perspectives on the safety and biocompatibility of dye compounds, which may contribute to developing improved strategies for acquired amyloidogenesis.

Guidelines for Antibiotics Prescription in Critically Ill Patients.

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Epigenetic differences in the tumor suppressor genes MLH1 and p16INK4a between Nepalese and Swedish patients with colorectal cancer.

Objectives: Colorectal cancer (CRC) is one of the most prevalent cancer types worldwide, exhibiting significant variance in incidence rates across different ethnicities and geographical regions. Notably, there is a rising incidence of CRC among younger adults, particularly evident in advanced stages, with a more pronounced trend observed in developing nations. Epigenetic alterations potentially play a role in the early onset of CRC and could elucidate interpopulation disparities. This study aimed to examine DNA methylation levels in the tumor suppressor genes MLH1 and p16INK4a, comparing Nepalese and Swedish patients with CRC. Methods: Patients who underwent CRC surgery at Tribhuvan University Teaching Hospital, Nepal (n=39), and Sahlgrenska University Hospital, Sweden (n=39) were included. Demographic and clinicopathological data were analyzed, and pyrosequencing was employed to determine methylation levels in the MLH1 promoter region and the first exon of p16INK4a in tumor tissues and adjacent mucosa located 10 cm from the tumor site. Subsequently, methylation status was compared between Nepalese and Swedish patients and correlated with clinicopathological parameters. Results: Nepalese and Swedish patients displayed equal levels of MLH1 and p16INK4a methylation in tumors, but Nepalese patients exhibited a significantly higher level of MLH1 methylation in mucosa compared to Swedish patients (p=0.0008). Moreover, a greater proportion of Nepalese patients showed MLH1 methylation in mucosa compared to Swedish patients (31 vs. 2.6 %). Aberrant methylation of p16INK4a was also observed in the mucosa of Nepalese patients, characterized by high methylation at specific sites rather than uniform methylation across CpG sites. There were no significant differences in methylation levels based on tumor location among Nepalese patients, whereas Swedish patients exhibited higher methylation in right- compared to left-sided colon tumors. Swedish patients showed an increase in p16INK4a methylation in tumors with advancing age. Conclusions: Nepalese and Swedish patients displayed equal levels of MLH1 and p16INK4a methylation in tumors. In contrast, Nepalese patients had a higher level of MLH1 methylation as well as aberrant methylation of p16INK4a in mucosa compared to Swedish patients. These epigenetic differences may be linked to environmental and lifestyle factors. Ongoing research will further explore whether hypermethylation in the mucosa of Nepalese patients is associated with tumorigenesis and its potential utility in screening high-risk patients or predicting recurrence.

Comparative genomics reveal unique markers to monitor by routine PCR assay bioinoculant of Sphingobium indicum B90A in hexachlorocyclohexane (HCH) contaminated soils.

Bioinoculants of Sphingobium indicum B90A have been used to decontaminate hexachlorocyclohexane (HCH)-contaminated soils in the past. There is no selective or convenient method available to track the added B90A in HCH-contaminated soils in the presence of several native sphingomonads. Here, we describe a method, BioMarkTrack, for tracking B90A bioinoculant by simple amplification of the B90A specific biomarker genes. Whole-genome sequence data of 120 different genera of sphingomonads (Sphingobium, Novosphingobium, Sphingomonas, Sphingopyxis, and Sphingosinicella) were retrieved from the NCBI database and annotated. Intra- and inter-genus similarity searches, including the genome of B90A as a reference was conducted. 122 unique gene sequences were identified in strain B90A, out of which 45 genes were selected that showed no similarity with the NCBI non-redundant (NR) database or gene sequences in the publicly available database. Primers were designed for amplification of 4 biomarkers. To validate the biomarkers B90A tracking efficacy in bioaugmented soils, a microcosm study was conducted in which sterile garden and HCH-contaminated dumpsite soils were amended with strain B90A. Amplification of the biomarker was observed both in sterile garden soil and HCH-contaminated dumpsite soil but not in control (lacking B90A) samples. Further, the primer set was used to track B90A in a bioremediation field trial soil, demonstrating the convenience and efficiency of the simple PCR-based method, which can be employed for tracking B90A in bioaugmented soils. The approach as presented here can be employed on different bioinoculants to identify unique biomarkers and then tracking these organisms during bioremediation. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01321-7.

Primary Alveolar Rhabdomyosarcoma of the Thyroid: A Case Report.

Malignancies in paediatric age group are the second leading cause of death, next only to accidents. The variety of malignancies involving the head and neck region in paediatric age group is bewildering. Rhabdomyosarcoma of thyroid gland is one such entity very rarely seen. We present the case of an adolescent who presented with a neck mass and suffered rapid deterioration. Establishment of final diagnosis was possible only because of a skilfully performed pathological examination which revealed a thyroid gland rhabdomyosarcoma. An alveolar variety of rhabdomyosarcoma presenting in the thyroid gland is extremely rare. To the best of our knowledge, only two cases of the aforementioned are documented as yet. Through this report, we aim at highlighting the possibility of such an occurrence and vigilance on part of the treating surgeon so that timely intervention can be instituted.

Prevalence and Clinical Implications of Autoantibodies in Juvenile Dermatomyositis: A Single-Center Experience From India.

OBJECTIVE: ​​This study aimed to characterize the profile of myositis-specific and myositis-associated autoantibodies (MSAs/MAAs) in an Indian cohort of juvenile dermatomyositis (JDM) patients and correlate them with clinical features and outcomes. METHODS: Forty-three children diagnosed with JDM were enrolled for this observational study. Clinical details (presentation, course, and outcome) were noted in a predesigned proforma. Serum samples were tested for 16 MSAs/MAAs by line immunoassay. MSAs/MAAs were correlated with clinical features and outcome (defined as a complete clinical response [≥6 months' disease inactivity on medication] or complete remission [≥6 months' inactivity off all drugs]). RESULTS: Thirty-five subjects (81.4%) had at least 1 MSA/MAA detected. The most common antibodies were anti-NXP2 (n = 13, 30.2%), anti-TIF1γ (n = 10, 23.2%), and anti-MDA-5 (n = 8, 18.6%). No patient had anti-Ku, anti-Pm Scl-100, anti-PL-12, anti-EJ, anti-OJ, or anti-Ro52. Thirty-two patients (74.4%) attained a complete clinical response over a median follow-up duration of 14 months, among which 6 (13.9%) achieved complete remission over a median follow-up duration of 30 months. Anti-TIF1γ was associated with younger age at onset (≤3 years) (odds ratio [OR], 6.25; 95% confidence interval [CI], 1.15-34.12; p = 0.034) and disease flares after attaining complete response (OR, 10.18; 95% CI, 1.64-70.93; p = 0.013). Patients with anti-NXP2 had higher odds of severe muscular weakness (OR, 3.73; 95% CI, 0.95-14.59; p = 0.058) and truncal weakness (OR, 3.89; 95% CI, 0.97-15.64; p = 0.056). One child with anti-MDA-5 positivity had interstitial lung disease. We found no association between the MSA/MAA profile and the achievement of complete clinical response or remission. CONCLUSIONS: MSAs/MAAs were identified in 81% of children with JDM in our study, which is higher than most other studies. The most frequently observed antibodies displayed a pattern consistent with other studies. Anti-TIF1γ was associated with a younger age at onset and disease flares even after attaining a complete clinical response. Anti-NXP2 had higher odds of severe muscular weakness. These observations suggest consistency in certain phenotypic associations observed across geographic boundaries.

Navigating the Complexity of Alternating Hemiplegia in Childhood: A Comprehensive Review.

Alternating hemiplegia of childhood (AHC) is a complex neurodevelopmental disorder characterized by paroxysmal and transient events of unilateral or bilateral paresis, usually occurring before 18 months of age. Mutations in the ATP1A3 gene, mainly p.Asp801Asn, p.Glu815Lys, and p.Gly947Arg at the protein level, are found in around 80% of the individuals with AHC. Interestingly, these mutations reflect the degree of severity of the neurological symptoms (p.Glu815Lys > p.Asp801Asn > p.Gly947Arg). Some channels involved in this disorder are N-type voltage-gated calcium channels, ATP-sensitive potassium channels, and the sodium/calcium exchanger. In this context, the management of AHC should be divided into the treatment of attacks, prophylactic treatment, and management of comorbidities commonly found in this group of individuals, including epilepsy, attention-deficit/hyperactivity disorder, aggressive behavior, cognitive impairment, movement disorders, and migraine. The importance of an integrated approach with a multidisciplinary team, such as neuropsychologists and dietitians, is worth mentioning, as well as the follow-up with a neurologist. In the present study, we propose new diagnostic criteria for AHC, dividing it into clinical, laboratory, supporting, and atypical features. Also, we review the location of the mutations in the ATP1A3 protein of individuals with AHC, rapid-onset dystonia-parkinsonism (RDP) variants, and early infantile epileptic encephalopathy (variants with hemiplegic attack). We also include a section about the animal models for ATP1A3 disorders.

High-Throughput Bioprinting of Spheroids for Scalable Tissue Fabrication.

Tissue biofabrication that replicates an organ-specific architecture and function requires physiologically-relevant cell densities. Bioprinting using spheroids has the potential to create constructs with native cell densities, but its application is limited due to the lack of practical, scalable techniques. This study presents HITS-Bio (High-throughput Integrated Tissue Fabrication System for Bioprinting), a novel multiarray spheroid bioprinting technology enabling scalable tissue fabrication by rapidly positioning a number of spheroids simultaneously using a digitally-controlled nozzle array (DCNA) platform. HITS-Bio achieves an unprecedented speed, an order of magnitude faster compared to existing techniques while maintaining high cell viability (>90%). The platform's ability to pattern multiple spheroids simultaneously enhances fabrication rates proportionally to the size of DCNA used. The utility of HITS-Bio was exemplified in multiple applications, including intraoperative bioprinting with microRNA transfected spheroids for calvarial bone regeneration (∼30 mm 3 ) in a rat model achieving a near-complete defect closure (∼91% in 3 weeks and ∼96% in 6 weeks). Additionally, the successful fabrication of scalable cartilage constructs (1 cm 3 ) containing ∼600 chondrogenic spheroids highlights its high-throughput efficiency (under 40 min per construct) and potential for repairing volumetric tissue defects.

A Rare Case of Brucellosis with Multivalvular Endocarditis and Complete Heart Block.

BACKGROUND: Brucellosis is a public health concern that affects multiple organs. However, cardiovascular problems arise infrequently, affecting fewer than 2% of cases, typically presenting as endocarditis. CASE PRESENTATION: A 50-year male was admitted with low-grade fever, night sweats, weight loss (13 kg), malaise, and generalized weakness for the past 6 months. On clinical examination, he was febrile with 39.0°C, an average heart rate of 54 bpm, and 100/40 mmHg blood pressure. On cardiovascular examination, S1 and S2 were soft with pan systolic murmur present in the mitral area, and the early diastolic murmur was present in the left third intercostal space. Electrocardiography was suggestive of third-degree heart block with AV dissociation. Transthoracic echocardiography showed mobile vegetations attached to multiple valves- an aortic valve (18.2x11.9 mm) and a mitral valve (2.9x7.5 mm) with perivalvular abscess. He was given oral doxycycline (100 mg B.D.) and rifampicin (600 mg/day); the patient responded, but the AV block did not resolve. CONCLUSION: This report has drawn attention to multivalvular involvement and cardiac rhythm abnormalities in Brucellosis (in this case, A.V. dissociation was present) because early diagnosis and treatment can cause a significant decrease in morbidity as well as mortality by appropriate treatment.

Effect of male parental gamma irradiation on host suitability of its F1 progeny of a lepidopteran tropical pest, Spodoptera litura (Fabr.) towards development and virulence of entomopathogenic nematodes, Steinernema thermophilum.

The suitability of F1 progeny insect larvae of the irradiated male parent, Spodoptera litura (Fabr.) for infective juveniles (IJs) of entomopathogenic nematodes (EPN), Steinernema thermophilum was assessed to comprehend the feasibility of combining EPNs with nuclear pest control tactic. As compared to the control, the IJs induced faster host mortality with reduced proliferation in F1 host larvae. IJs derived from F1 host larvae exhibited almost similar proliferation capacity on normal hosts as in control. Further, the molecular basis of EPNs induced mortality in F1 host larvae was evaluated. Dual stress of EPN infection and irradiation induced downregulation of the relative mRNA expression of antimicrobial genes and upregulated expression of antioxidative genes. A pronounced effect of EPNs in association with irradiation stress was apparent on host mortality. Radiation induced sterile F1 insect larvae of S. litura acted as a reasonably suitable host for EPNs and also provided the environment for developing viable EPNs for their potential use as biocontrol agents.

Systematic review with expert consensus on use of extracorporeal hemoadsorption in septic shock: An Indian perspective.

BACKGROUND: Septic shock is a severe form of sepsis characterised by deterioration in circulatory and cellular-metabolic parameters. Despite standard therapy, the outcomes are poor. Newer adjuvant therapy, such as CytoSorb® extracorporeal haemoadsorption device, has been investigated and shown promising outcome. However, there is a lack of some guidance to make clinical decisions on the use of CytoSorb® haemoadsorption as an adjuvant therapy in septic shock in Indian Setting. Therefore, this expert consensus was formulated. AIM: To formulate/establish specific consensus statements on the use of CytoSorb® haemoadsorption treatment based on the best available evidence and contextualised to the Indian scenario. METHODS: We performed a comprehensive literature on CytoSorb® haemoadsorption in sepsis, septic shock in PubMed selecting papers published between January 2011 and March 2023 2021 in English language. The statements for a consensus document were developed based on the summarised literature analysis and identification of knowledge gaps. Using a modified Delphi approach combining evidence appraisal and expert opinion, the following topics related to CytoSorb® in septic shock were addressed: need for adjuvant therapy, initiation timeline, need for Interleukin -6 levels, duration of therapy, change of adsorbers, safety, prerequisite condition, efficacy endpoints and management flowchart. Eleven expert members from critical care, emergency medicine, and the intensive care participated and voted on nine statements and one open-ended question. RESULTS: Eleven expert members from critical care, emergency medicine, and the intensive care participated and voted on nine statements and one open-ended question. All 11 experts in the consensus group (100%) participated in the first, second and third round of voting. After three iterative voting rounds and adapting two statements, consensus was achieved on nine statements out of nine statements. The consensus expert panel also recognised the necessity to form an association or society that can keep a registry regarding the use of CytoSorb® for all indications in the open-ended question (Q10) focusing on "future recommendations for CytoSorb® therapy". CONCLUSION: This Indian perspective consensus statement supports and provides guidance on the use of CytoSorb® haemoadsorption as an adjuvant treatment in patients with septic shock to achieve optimal outcomes.

Relationship Between COVID-19 and Linezolid-Resistant Enterococci: A Retrospective Single-Center Study.

AIM AND OBJECTIVES: To evaluate the correlation between whether the COVID-19 pandemic turned out to be a great premise for increasing the incidence of linezolid resistance infections. MATERIALS AND METHOD: The current retrospective study included data from March 2018 to March 2023 from a single center. The clinical records of the patients were reviewed to extract clinical data. Data gathered from medical records included demographic information, the type of specimen taken, the organism identified, and its sensitivity. Antibiotic susceptibility testing and bacterial identification are both done using the fully automated VITEK system. RESULTS: The total number of samples collected in all the groups, i.e., Group 1 (PRE-COVID), Group 2 (COVID), and Group 3 (POST-COVID), were 201, 127, and 1315, respectively. Out of a total of 201 samples in Group 1, i.e., from March 2018 to February 2020, 47 (23.38%) samples were collected from blood, 104 (51.74%) samples were collected from urine, and the rest of the samples were collected from other sources (pus, sputum, wound, stool, pleural fluid, etc.). In Group 2, i.e., from March 2020 to February 2021, the total number of samples collected was 127, of which 21 were collected from blood, 86 were from urine, and the remaining 20 samples were from other sources. A total of 1315 samples were collected between March 2021 and February 2023, i.e., in Group 3, 598 samples were collected from blood and 548 samples from urine. The most common isolates in the study were Enterococcus faecalis (35.7%) and Enterococcus faecium (61.0%). CONCLUSION: A new threat seems to be emerging in the era of COVID-19, the Enterococcus genus. Though the mechanism remains unidentified, the viral infection seems to cause changes in the bacterial flora, favoring Enterococcus and increasing gut permeability, which provides the perfect environment for Enterococcus bacteria to develop invasive infections. In our study, the prevalence of linezolid resistance was 18.2% for five years.

Simultaneous Liver and Kidney Transplantation in a Patient With Telomere Biology Disorder: A Case Study.

Organ transplantation is the primary therapy for organ failure caused by telomere biology disorder (TBD). We describe the first documented case of simultaneous liver and kidney transplantation (SLKTx) for TBD, although the diagnosis of TBD was reached only three months following SLKTx. The patient was born prematurely, displayed growth retardation, and developed chronic kidney and liver diseases. His pre-SLKTx autoimmune, metabolic, and viral assessments were negative, and persistent pancytopenia (bone marrow cellularity 70-80%) was attributed to renal disease-associated bone marrow changes. Following SLKTx, he was discharged with stable graft function on tacrolimus and prednisolone. Although mycophenolate mofetil was discontinued on the second postoperative day, his pancytopenia persisted. Despite extensive evaluations, including drug, immune, nutritional, and viral assessments, all results were negative. A bone marrow biopsy conducted three months post-transplant revealed significant hypocellularity (40-50%). Whole genome sequencing revealed a likely pathogenic variant of the TINF2 gene. The patient was subsequently treated with danazol. At the nine-month follow-up post-SLKTx, he exhibited stable graft function and improved cell counts while maintaining triple-drug immunosuppression. Given the lack of uniform diagnostic criteria for TBD, healthcare providers must be vigilant with patients presenting with multi-organ failure and persistent cytopenias. Effective pre-transplant screening for TBD can lead to timely diagnoses, better management, and improved post-transplant outcomes.

A Review on Comparison of Allopathic Medicines to other Drug Therapies in the Management of Asthma.

Asthma, is a chronic disease of the airways and is characterized by exacerbations of bronchospasm and noticeable airway inflammation. Current asthma therapy has emerged from naturally occurring compounds through rational pharmaceutical advancements, and it is very beneficial. In this review, we have discussed the different drug therapies i.e., Ayurvedic, Homeopathic, Unani, and Allopathic affecting asthma treatment. Allopathic medicines are used as a controller medication for regular maintenance of asthma i.e., long-acting ß-agonists, inhaled corticosteroids, anti-leukotriene medicines, and novel biologic agents. Pharmacological research is more important in generating effective, long-lasting, and safe asthma treatments, but it has been difficult to produce new classes of anti-asthmatic therapies. A combination inhaler that contains a long-acting ß2-agonist and a corticosteroid is currently the "gold standard" for treating asthma. Allopathic treatments for asthma have been proven effective in reducing the probability of asthma attacks and for improving symptoms along with lung functions as compared to other therapies. The level of asthma management and the possible risk of future worsening are used to determine the treatment's strategies. This review article describes the comparison of allopathic therapy of asthma with homeopathy, ayurvedic and Unani system and gives justification supported by a number of case studies for being allopathic, a better therapy when compared with others.

Nested Biofabrication: Matryoshka-Inspired Intra-Embedded Bioprinting.

Engineering functional tissues and organs remains a fundamental pursuit in bio-fabrication. However, the accurate constitution of complex shapes and internal anatomical features of specific organs, including their intricate blood vessels and nerves, remains a significant challenge. Inspired by the Matryoshka doll, here a new method called "Intra-Embedded Bioprinting (IEB)" is introduced building upon existing embedded bioprinting methods. a xanthan gum-based material is used which served a dual role as both a bioprintable ink and a support bath, due to its unique shear-thinning and self-healing properties. IEB's capabilities in organ modeling, creating a miniaturized replica of a pancreas using a photocrosslinkable silicone composite is demonstrated. Further, a head phantom and a Matryoshka doll are 3D printed, exemplifying IEB's capability to manufacture intricate, nested structures. Toward the use case of IEB and employing an innovative coupling strategy between extrusion-based and aspiration-assisted bioprinting, a breast tumor model that included a central channel mimicking a blood vessel, with tumor spheroids bioprinted in proximity is developed. Validation using a clinically-available chemotherapeutic drug illustrated its efficacy in reducing the tumor volume via perfusion over time. This method opens a new way of bioprinting enabling the creation of complex-shaped organs with internal anatomical features.

Intraoperative bioprinting of human adipose-derived stem cells and extra-cellular matrix induces hair follicle-like downgrowths and adipose tissue formation during full-thickness craniomaxillofacial skin reconstruction.

Craniomaxillofacial (CMF) reconstruction is a challenging clinical dilemma. It often necessitates skin replacement in the form of autologous graft or flap surgery, which differ from one another based on hypodermal/dermal content. Unfortunately, both approaches are plagued by scarring, poor cosmesis, inadequate restoration of native anatomy and hair, alopecia, donor site morbidity, and potential for failure. Therefore, new reconstructive approaches are warranted, and tissue engineered skin represents an exciting alternative. In this study, we demonstrated the reconstruction of CMF full-thickness skin defects using intraoperative bioprinting (IOB), which enabled the repair of defects via direct bioprinting of multiple layers of skin on immunodeficient rats in a surgical setting. Using a newly formulated patient-sourced allogenic bioink consisting of both human adipose-derived extracellular matrix (adECM) and stem cells (ADSCs), skin loss was reconstructed by precise deposition of the hypodermal and dermal components under three different sets of animal studies. adECM, even at a very low concentration such as 2 % or less, has shown to be bioprintable via droplet-based bioprinting and exhibited de novo adipogenic capabilities both in vitro and in vivo. Our findings demonstrate that the combinatorial delivery of adECM and ADSCs facilitated the reconstruction of three full-thickness skin defects, accomplishing near-complete wound closure within two weeks. More importantly, both hypodermal adipogenesis and downgrowth of hair follicle-like structures were achieved in this two-week time frame. Our approach illustrates the translational potential of using human-derived materials and IOB technologies for full-thickness skin loss.

Synergistic coupling between 3D bioprinting and vascularization strategies.

Three-dimensional (3D) bioprinting offers promising solutions to the complex challenge of vascularization in biofabrication, thereby enhancing the prospects for clinical translation of engineered tissues and organs. While existing reviews have touched upon 3D bioprinting in vascularized tissue contexts, the current review offers a more holistic perspective, encompassing recent technical advancements and spanning the entire multistage bioprinting process, with a particular emphasis on vascularization. The synergy between 3D bioprinting and vascularization strategies is crucial, as 3D bioprinting can enable the creation of personalized, tissue-specific vascular network while the vascularization enhances tissue viability and function. The review starts by providing a comprehensive overview of the entire bioprinting process, spanning from pre-bioprinting stages to post-printing processing, including perfusion and maturation. Next, recent advancements in vascularization strategies that can be seamlessly integrated with bioprinting are discussed. Further, tissue-specific examples illustrating how these vascularization approaches are customized for diverse anatomical tissues towards enhancing clinical relevance are discussed. Finally, the underexplored intraoperative bioprinting (IOB) was highlighted, which enables the direct reconstruction of tissues within defect sites, stressing on the possible synergy shaped by combining IOB with vascularization strategies for improved regeneration.

Intraoperative Bioprinting of Human Adipose-derived Stem cells and Extra-cellular Matrix Induces Hair Follicle-Like Downgrowths and Adipose Tissue Formation during Full-thickness Craniomaxillofacial Skin Reconstruction.

Craniomaxillofacial (CMF) reconstruction is a challenging clinical dilemma. It often necessitates skin replacement in the form of autologous graft or flap surgery, which differ from one another based on hypodermal/dermal content. Unfortunately, both approaches are plagued by scarring, poor cosmesis, inadequate restoration of native anatomy and hair, alopecia, donor site morbidity, and potential for failure. Therefore, new reconstructive approaches are warranted, and tissue engineered skin represents an exciting alternative. In this study, we demonstrated the reconstruction of CMF full-thickness skin defects using intraoperative bioprinting (IOB), which enabled the repair of defects via direct bioprinting of multiple layers of skin on immunodeficient rats in a surgical setting. Using a newly formulated patient-sourced allogenic bioink consisting of both human adipose-derived extracellular matrix (adECM) and stem cells (ADSCs), skin loss was reconstructed by precise deposition of the hypodermal and dermal components under three different sets of animal studies. adECM, even at a very low concentration such as 2% or less, has shown to be bioprintable via droplet-based bioprinting and exhibited de novo adipogenic capabilities both in vitro and in vivo . Our findings demonstrate that the combinatorial delivery of adECM and ADSCs facilitated the reconstruction of three full-thickness skin defects, accomplishing near-complete wound closure within two weeks. More importantly, both hypodermal adipogenesis and downgrowth of hair follicle-like structures were achieved in this two-week time frame. Our approach illustrates the translational potential of using human-derived materials and IOB technologies for full-thickness skin loss.

The heparin-binding hemagglutinin protein of Mycobacterium tuberculosis is a nucleoid-associated protein.

Nucleoid-associated proteins (NAPs) regulate multiple cellular processes such as gene expression, virulence, and dormancy throughout bacterial species. NAPs help in the survival and adaptation of Mycobacterium tuberculosis (Mtb) within the host. Fourteen NAPs have been identified in Escherichia coli; however, only seven NAPs are documented in Mtb. Given its complex lifestyle, it is reasonable to assume that Mtb would encode for more NAPs. Using bioinformatics tools and biochemical experiments, we have identified the heparin-binding hemagglutinin (HbhA) protein of Mtb as a novel sequence-independent DNA-binding protein which has previously been characterized as an adhesion molecule required for extrapulmonary dissemination. Deleting the carboxy-terminal domain of HbhA resulted in a complete loss of its DNA-binding activity. Atomic force microscopy showed HbhA-mediated architectural modulations in the DNA, which may play a regulatory role in transcription and genome organization. Our results showed that HbhA colocalizes with the nucleoid region of Mtb. Transcriptomics analyses of a hbhA KO strain revealed that it regulates the expression of ∼36% of total and ∼29% of essential genes. Deletion of hbhA resulted in the upregulation of ∼73% of all differentially expressed genes, belonging to multiple pathways suggesting it to be a global repressor. The results show that HbhA is a nonessential NAP regulating gene expression globally and acting as a plausible transcriptional repressor.