Sonosensitive Cavitation Nuclei-A Customisable Platform Technology for Enhanced Therapeutic Delivery.

Ultrasound-mediated cavitation shows great promise for improving targeted drug delivery across a range of clinical applications. Cavitation nuclei-sound-sensitive constructs that enhance cavitation activity at lower pressures-have become a powerful adjuvant to ultrasound-based treatments, and more recently emerged as a drug delivery vehicle in their own right. The unique combination of physical, biological, and chemical effects that occur around these structures, as well as their varied compositions and morphologies, make cavitation nuclei an attractive platform for creating delivery systems tuned to particular therapeutics. In this review, we describe the structure and function of cavitation nuclei, approaches to their functionalization and customization, various clinical applications, progress toward real-world translation, and future directions for the field.

Global and regional genetic diversity of HIV-1 in 2010-21: systematic review and analysis of prevalence.

BACKGROUND: The extensive global genetic diversity of HIV-1 poses a major challenge to HIV vaccine development. We aimed to determine recent estimates of and changes in the global and regional distributions of HIV-1 genetic variants. METHODS: We conducted a systematic literature review by searching PubMed, Embase, Global Health, and CINAHL for studies containing country-specific HIV-1 subtyping data, published between Jan 1, 2010 and Sep 16, 2022. The proportions of HIV-1 subtypes, circulating recombinant forms (CRFs), and unique recombinant forms (URFs) in each country were weighted by UNAIDS estimates of the numbers of people living with HIV (PLHIV) in each country to obtain regional and global prevalence estimates of HIV-1 subtypes, CRFs, and URFs with 95% CIs for the time periods 2010-15 and 2016-21. The protocol is registered with PROSPERO, CRD42017067164. FINDINGS: We obtained 1044 datasets, containing HIV-1 subtyping data from 653 013 PLHIV from 122 countries in 2010-2021. In 2016-2021, subtype C accounted for 50·4% (95% CI 50·2-50·7; n=18 570 462 of 36 823 798) of global HIV infections, subtype A for 12·4% (12·2-12·6; n=4 571 250), subtype B for 11·3% (11·1-11·5; n=4 157 686), subtype G for 2·9% (2·9-3·0; n=1 083 568), subtype D for 2·6% (2·5-2·7; n=945 815), subtype F for 0·9% (0·8-0·9; n=316 724), CRFs for 15·1% (14·9-15·3; n=5 564 566), and URFs for 2·0% (1·9-2·1; n=733 374). Subtypes H, J, and K each accounted for 0·1% or less of infections. Compared with 2010-15, we observed significant (p<0·0001) increases in global proportions of subtype A (0·9%, 95% CI 0·7 to 1·1) and subtype C (3·4%, 3·0 to 3·7) and decreases in subtype D (-0·5%, -0·6 to -0·4), subtype G (-0·8%, -1·0 to -0·7), CRFs (-1·0%, -1·3 to -0·8), and URFs (-1·8%, -1·9 to -1·7), with no changes for subtypes B and F. The global proportion of infections attributed to recombinants decreased from 21·6% (95% CI 21·4 to 21·7; n=7 099 252 of 32 622 808) in 2010-15 to 19·3% (19·1 to 19·5; n=7 094 694 of 36 823 798) in 2016-21 (-2·3%, 95% CI -2·6 to -2·0; p<0·0001). Regional distributions of HIV-1 variants were complex and evolving, with global trends in the prevalence of HIV-1 variants supported by trends across the regions. INTERPRETATION: Global and regional HIV-1 genetic diversity are complex and continue to evolve. Continued and improved surveillance of HIV-1 variants remains vital for HIV vaccine development and implementation. FUNDING: None.

Comparison of the angiogenic efficacy of conventional leukocyte- and platelet-rich fibrin versus low-speed advanced platelet-rich fibrin: An in vitro chorioallantoic membrane assay study.

BACKGROUND: Platelet-rich fibrin (PRF) is widely used in periodontics for its wound healing potential. Two major variations of PRF are the original leukocyteand platelet-rich fibrin (L-PRF) and the modified lowspeed advanced PRF (A-PRF). OBJECTIVES: The aim of the present study was to evaluate and compare the conventional L-PRF protocol and the low-speed A-PRF protocol in terms of angiogenic potential of PRF, using an in vivo chorioallantoic membrane (CAM) assay. MATERIAL AND METHODS: Fifteen fertile Giriraja eggs were procured and after a 3-day incubation period, randomly allotted into 3 groups: control; L-PRF; and A-PRF. A total of 20 mL of blood was collected from systemically healthy male volunteers aged 18-24 years, using a standard protocol. The PRF samples were inoculated on the CAM of the eggs. On the 10th day, the eggs were reopened and photographed. The parameters assessed were the number, length, size, and density of blood vessels, as well as the number of junctions formed. The photographs were analyzed using the ImageJ and ProgRes® CapturePro software. RESULTS: Seven days after inoculation, both the A-PRF and L-PRF groups exhibited significantly better results than the control group in terms of the number (59.20 ±6.61 vs. 48.80 ±5.07 vs. 19.20 ±6.98), length (25,000 ±1,813.10 µm vs. 17,000 ±282.90 µm vs. 8,000 ±184.49 µm), size (230,000 ±15,054.00 µm2 vs. 200,000 ±8,295.27 µm2 vs. 150,000 ±4,105.16 µm2), and density (central: 9,100 ±296.78 vs. 5,370 ±272.42 vs. 1,420 ±564.36; peripheral: 9,094 ±400.14 vs. 3,370 ±479.39 vs. 5,420 ±746.73) of blood vessels, as well as the number of junctions formed (52 ±3.81 vs. 41 ±1.58 vs. 33 ±4.64), respectively. CONCLUSIONS: The angiogenic potential was increased by the exposure to both L-PRF and A-PRF. However, A-PRF demonstrated statistically significant benefits in terms of the number, length, size, and density of blood vessels, as well as the number of junctions formed in comparison with the control and L-PRF groups.

Survival Outcomes of Breast Cancer Patients in South India Over 20 Years.

OBJECTIVE: The study aimed to investigate the distribution and clinicopathologic features of breast cancer patients in South India, while also examining the overall survival (OS) and identifying predictive factors affecting it. Additionally, we aimed to assess the influence of risk factors on Disease Free Survival (DFS) and Distant Disease-Free Survival (DDFS). METHODS: This retrospective cohort study on breast cancer trends used comprehensive follow-up including regular patient contact, medical record review and collaboration with healthcare providers. Patients without follow-up information for more than 12 months were contacted by telephone, while those with no follow-up after 2 years were labelled as lost to follow-up. RESULTS: A total of 3256 patients were identified from a single cancer institute in India. The median follow-up time was 8.1 years. The 5-year survival rates were 89%, 84%, 85%, 88% and 10-year were 82%, 78%, 79%, 83% for luminal cancers, Triple Negative Breast Cancers, HER2 enriched and luminal with HER2 enriched respectively. CONCLUSION: Poorer survival rates were seen among those with pT3/4 tumors, nodal involvement at diagnosis, Estrogen receptor negative status, high Ki67 proliferative index and higher TNM stage at diagnosis of the disease. Although our patients were younger and had more aggressive types of cancer, their DFS, DDFS and overall survival were comparable to other developed nations.

A Longitudinal Elective Facilitates Point-of-Care Ultrasonography Education for Medical Students: An Observational Study.

OBJECTIVE: Determine if a longitudinal point-of-care ultrasonography (POCUS) elective for medical students is effective in improving POCUS knowledge. METHODS: We share the format of our longitudinal POCUS elective for medical students. To evaluate the efficacy of our longitudinal elective, we compare the difference between pre-elective and post-elective scores on a POCUS test using a paired t-test with threshold of statistical significance of p ≤ .05. We also share the results of a post-elective survey evaluating the effectiveness and quality of the longitudinal POCUS elective. RESULTS: Pretest mean score was 56.3% (σ = 13.6), while posttest mean score was 73.3% (σ = 9.4), with an average score improvement of 17.0% (95% CI 9.9-24.0%, p < .0001). All students strongly or moderately agreed that they would recommend the elective to future medical students, that they were more confident with their POCUS skills after completing the elective, that the time commitment of the elective was appropriate, and that they felt they had the time to fit the elective into their schedule as a medical school student. Most students (56.7%) strongly or moderately agreed that the knowledge gained from the POCUS elective had helped them in their clinical rotations. CONCLUSIONS: Our longitudinal POCUS curriculum subjectively and objectively improves medical students' POCUS knowledge while remaining accessible to students. We share our unique longitudinal POCUS elective curriculum, the format of which and its benefits are transferable to other medical schools. Through this, we hope to provide others with ideas on how they may implement a longitudinal POCUS elective.

A Translation-Independent Directed Evolution Strategy to Engineer Aminoacyl-tRNA Synthetases.

Using directed evolution, aminoacyl-tRNA synthetases (aaRSs) have been engineered to incorporate numerous noncanonical amino acids (ncAAs). Until now, the selection of such novel aaRS mutants has relied on the expression of a selectable reporter protein. However, such translation-dependent selections are incompatible with exotic monomers that are suboptimal substrates for the ribosome. A two-step solution is needed to overcome this limitation: (A) engineering an aaRS to charge the exotic monomer, without ribosomal translation; (B) subsequent engineering of the ribosome to accept the resulting acyl-tRNA for translation. Here, we report a platform for aaRS engineering that directly selects tRNA-acylation without ribosomal translation (START). In START, each distinct aaRS mutant is correlated to a cognate tRNA containing a unique sequence barcode. Acylation by an active aaRS mutant protects the corresponding barcode-containing tRNAs from oxidative treatment designed to damage the 3'-terminus of the uncharged tRNAs. Sequencing of these surviving barcode-containing tRNAs is then used to reveal the identity of the aaRS mutants that acylated the correlated tRNA sequences. The efficacy of START was demonstrated by identifying novel mutants of the Methanomethylophilus alvus pyrrolysyl-tRNA synthetase from a naïve library that enables incorporation of ncAAs into proteins in living cells.

In vivo dendritic cell reprogramming for cancer immunotherapy.

Immunotherapy can lead to long-term survival for some cancer patients, yet generalized success has been hampered by insufficient antigen presentation and exclusion of immunogenic cells from the tumor microenvironment. Here, we developed an approach to reprogram tumor cells in vivo by adenoviral delivery of the transcription factors PU.1, IRF8, and BATF3, which enabled them to present antigens as type 1 conventional dendritic cells. Reprogrammed tumor cells remodeled their tumor microenvironment, recruited, and expanded polyclonal cytotoxic T cells; induced tumor regressions; and established long-term systemic immunity in multiple mouse melanoma models. In human tumor spheroids and xenografts, reprogramming to immunogenic dendritic-like cells progressed independently of immunosuppression, which usually limits immunotherapy. Our study paves the way for human clinical trials of in vivo immune cell reprogramming for cancer immunotherapy.

Clinical trials in Charcot-Marie-Tooth disorders: a retrospective and preclinical assessment.

Objective: This study aimed to evaluate the progression of clinical and preclinical trials in Charcot-Marie-Tooth (CMT) disorders. Background: CMT has historically been managed symptomatically and with genetic counseling. The evolution of molecular and pathologic understanding holds a therapeutic promise in gene-targeted therapies. Methods: ClinicalTrials.gov from December 1999 to June 2022 was data extracted for CMT with preclinical animal gene therapy trials also reviewed by PubMed search. Results: The number of active trials was 1 in 1999 and 286 in 2022. Academic settings accounted for 91% and pharmaceutical companies 9%. Of the pharmaceutical and academic trials, 38% and 28%, respectively, were controlled, randomized, and double-blinded. Thirty-two countries participated: the United States accounted for 26% (75/286). In total, 86% of the trials were classified as therapeutic: 50% procedural (21% wrist/elbow surgery; 22% shock wave and hydrodissection therapy), 23% investigational drugs, 15% devices, and 11% physical therapy. Sixty-seven therapeutic trials (49%) were designated phases 1-2 and 51% phases 3-4. The remaining 14% represent non-therapeutic trials: diagnostic testing (3%), functional outcomes (4%), natural history (4%), and standard of care (3%). One-hundred and three (36%) resulted in publications. Phase I human pharmaceutical trials are focusing on the safety of small molecule therapies (n = 8) and AAV and non-viral gene therapy (n = 3). Preclinical animal gene therapy studies include 11 different CMT forms including viral, CRISPR-Cas9, and nanoparticle delivery. Conclusion: Current CMT trials are exploring procedural and molecular therapeutic options with substantial participation of the pharmaceutical industry worldwide. Emerging drug therapies directed at molecular pathogenesis are being advanced in human clinical trials; however, the majority remain within animal investigations.

Reversible Microscale Assembly of Nanoparticles Driven by the Phase Transition of a Thermotropic Liquid Crystal.

The arrangement of nanoscale building blocks into patterns with microscale periodicity is challenging to achieve via self-assembly processes. Here, we report on the phase-transition-driven collective assembly of gold nanoparticles in a thermotropic liquid crystal. A temperature-induced transition from the isotropic to the nematic phase under anchoring-driven planar alignment leads to the assembly of individual nanometer-sized particles into arrays of micrometer-sized agglomerates, whose size and characteristic spacing can be tuned by varying the cooling rate. Phase field simulations coupling the conserved and nonconserved order parameters exhibit a similar evolution of the morphology as the experimental observations. This fully reversible process offers control over structural order on the microscopic level and is an interesting model system for the programmable and reconfigurable patterning of nanocomposites with access to micrometer-sized periodicities.

Conducting Polymer-ECM Scaffolds for Human Neuronal Cell Differentiation.

3D cell culture formats more closely resemble tissue architecture complexity than 2D systems, which are lacking most of the cell-cell and cell-microenvironment interactions of the in vivo milieu. Scaffold-based systems integrating natural biomaterials are extensively employed in tissue engineering to improve cell survival and outgrowth, by providing the chemical and physical cues of the natural extracellular matrix (ECM). Using the freeze-drying technique, porous 3D composite scaffolds consisting of poly(3,4-ethylene-dioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS), containing ECM components (i.e., collagen, hyaluronic acid, and laminin) are engineered for hosting neuronal cells. The resulting scaffolds exhibit a highly porous microstructure and good conductivity, determined by scanning electron microscopy and electrochemical impedance spectroscopy, respectively. These supports boast excellent mechanical stability and water uptake capacity, making them ideal candidates for cell infiltration. SH-SY5Y human neuroblastoma cells show enhanced cell survival and proliferation in the presence of ECM compared to PEDOT:PSS alone. Whole-cell patch-clamp recordings acquired from differentiated SHSY5Y cells in the scaffolds demonstrate that ECM constituents promote neuronal differentiation in situ. These findings reinforce the usability of 3D conducting supports as engineered highly biomimetic and functional in vitro tissue-like platforms for drug or disease modeling.

Triboelectric Yarns with Electrospun Functional Polymer Coatings for Highly Durable and Washable Smart Textile Applications.

Triboelectric generators are excellent candidates for smart textiles applications due to their ability to convert mechanical energy into electrical energy. Such devices can be manufactured into yarns by coating a conductive core with a triboelectric material, but current triboelectric yarns lack the durability and washing resistance required for textile-based applications. In this work, we develop a unique triboelectric yarn comprising a conducting carbon nanotube (CNT) yarn electrode coated with poly(vinylidene fluoride) (PVDF) fibers deposited by a customized electrospinning process. We show that the electrospun PVDF fibers adhere extremely well to the CNT core, producing a uniform and stable triboelectric coating. The PVDF-CNT coaxial yarn exhibits remarkable triboelectric energy harvesting during fatigue testing with a 33% power output improvement and a peak power density of 20.7 µW cm-2 after 200 000 fatigue cycles. This is potentially due to an increase in the active surface area of the PVDF fiber coating upon repeated contact. Furthermore, our triboelectric yarn meets standard textile industry benchmarks for both abrasion and washing by retaining functionality over 1200 rubbing cycles and 10 washing cycles. We demonstrate the energy harvesting and motion sensing capabilities of our triboelectric yarn in prototype textile-based applications, thereby highlighting its applicability to smart textiles.

Tailoring the biofunctionality of collagen biomaterials via tropoelastin incorporation and EDC-crosslinking.

Recreating the cell niche of virtually all tissues requires composite materials fabricated from multiple extracellular matrix (ECM) macromolecules. Due to their wide tissue distribution, physical attributes and purity, collagen, and more recently, tropoelastin, represent two appealing ECM components for biomaterials development. Here we blend tropoelastin and collagen, harnessing the cell-modulatory properties of each biomolecule. Tropoelastin was stably co-blended into collagen biomaterials and was retained after EDC-crosslinking. We found that human dermal fibroblasts (HDF), rat glial cells (Rugli) and HT1080 fibrosarcoma cells ligate to tropoelastin via EDTA-sensitive and EDTA-insensitive receptors or do not ligate with tropoelastin, respectively. These differing elastin-binding properties allowed us to probe the cellular response to the tropoelastin-collagen composites assigning specific bioactivity to the collagen and tropoelastin component of the composite material. Tropoelastin addition to collagen increased total Rugli cell adhesion, spreading and proliferation. This persisted with EDC-crosslinking of the tropoelastin-collagen composite. Tropoelastin addition did not affect total HDF and HT1080 cell adhesion; however, it increased the contribution of cation-independent adhesion, without affecting the cell morphology or, for HT1080 cells, proliferation. Instead, EDC-crosslinking dictated the HDF and HT1080 cellular response. These data show that a tropoelastin component dominates the response of cells that possess non-integrin based tropoelastin receptors. EDC modification of the collagen component directs cell function when non-integrin tropoelastin receptors are not crucial for cell activity. Using this approach, we have assigned the biological contribution of each component of tropoelastin-collagen composites, allowing informed biomaterial design for directed cell function via more physiologically relevant mechanisms. STATEMENT OF SIGNIFICANCE: Biomaterials fabricated from multiple extracellular matrix (ECM) macromolecules are required to fully recreate the native tissue niche where each ECM macromolecule engages with a specific repertoire of cell-surface receptors. Here we investigate combining tropoelastin with collagen as they interact with cells via different receptors. We identified specific cell lines, which associate with tropoelastin via distinct classes of cell-surface receptor. These showed that tropoelastin, when combined with collagen, altered the cell behaviour in a receptor-usage dependent manner. Integrin-mediated tropoelastin interactions influenced cell proliferation and non-integrin receptors influenced cell spreading and proliferation. These data shed light on the interplay between biomaterial macromolecular composition, cell surface receptors and cell behaviour, advancing bespoke materials design and providing functionality to specific cell populations.

Islet sympathetic innervation and islet neuropathology in patients with type 1 diabetes.

Dysregulation of glucagon secretion in type 1 diabetes (T1D) involves hypersecretion during postprandial states, but insufficient secretion during hypoglycemia. The sympathetic nervous system regulates glucagon secretion. To investigate islet sympathetic innervation in T1D, sympathetic tyrosine hydroxylase (TH) axons were analyzed in control non-diabetic organ donors, non-diabetic islet autoantibody-positive individuals (AAb), and age-matched persons with T1D. Islet TH axon numbers and density were significantly decreased in AAb compared to T1D with no significant differences observed in exocrine TH axon volume or lengths between groups. TH axons were in close approximation to islet α-cells in T1D individuals with long-standing diabetes. Islet RNA-sequencing and qRT-PCR analyses identified significant alterations in noradrenalin degradation, α-adrenergic signaling, cardiac ß-adrenergic signaling, catecholamine biosynthesis, and additional neuropathology pathways. The close approximation of TH axons at islet α-cells supports a model for sympathetic efferent neurons directly regulating glucagon secretion. Sympathetic islet innervation and intrinsic adrenergic signaling pathways could be novel targets for improving glucagon secretion in T1D.

Tunable bioactivity and mechanics of collagen-based tissue engineering constructs: A comparison of EDC-NHS, genipin and TG2 crosslinkers.

Due to its ubiquity and versatility in the human body, collagen is an ideal base material for tissue-engineering constructs. Chemical crosslinking treatments allow precise control of the biochemical and mechanical properties through macromolecular modifications to the structure of collagen. In this work, three key facets regarding the collagen crosslinking process are explored. Firstly, a comparison is drawn between the carbodiimide-succinimide (EDC-NHS) system and two emerging crosslinkers utilising alternate chemistries: genipin and tissue transglutaminase (TG2). By characterising the chemical changes upon treatment, the effect of EDC-NHS, genipin and TG2 crosslinking mechanisms on the chemical structure of collagen, and thus the mechanical properties conferred to the substrate is explored. Secondly, the relative importance of mechanical and biochemical cues on cellular phenomena are investigated, including cell viability, integrin-specific attachment, spreading and proliferation. Here, we observe that for human dermal fibroblasts, long-term, stable proliferation is preconditioned by the availability of suitable binding sites, irrespective of the substrate modulus post-crosslinking. Finally, as seen in the graphical abstract we show that by choosing the appropriate crosslinker chemistries, a materials selection map can be drawn for collagen films, encompassing both a range of tensile modulus and fibroblast proliferation which can be modified independently. Thus, in addition to a range of parameters that can be modified in collagen constructs, we demonstrate a route to obtaining tunable bioactivity and mechanics in collagen constructs is uncovered, that is exclusively driven by the crosslinking process.

MicroCT analysis of connectivity in porous structures: optimizing data acquisition and analytical methods in the context of tissue engineering.

Micro-computed X-ray tomography (MicroCT) is one of the most powerful techniques available for the three-dimensional characterization of complex multi-phase or porous microarchitectures. The imaging and analysis of porous networks are of particular interest in tissue engineering due to the ability to predict various large-scale cellular phenomena through the micro-scale characterization of the structure. However, optimizing the parameters for MicroCT data capture and analyses requires a careful balance of feature resolution and computational constraints while ensuring that a structurally representative section is imaged and analysed. In this work, artificial datasets were used to evaluate the validity of current analytical methods by considering the effect of noise and pixel size arising from the data capture, and intrinsic structural anisotropy and heterogeneity. A novel 'segmented percolation method' was developed to exclude the effect of anomalous, non-representative features within the datasets, allowing for scale-invariant structural parameters to be obtained consistently and without manual intervention for the first time. Finally, an in-depth assessment of the imaging and analytical procedures are presented by considering percolation events such as micro-particle filtration and cell sieving within the context of tissue engineering. Along with the novel guidelines established for general pixel size selection for MicroCT, we also report our determination of 3 µm as the definitive pixel size for use in analysing connectivity for tissue engineering applications.

Self-assembly of collagen bundles and enhanced piezoelectricity induced by chemical crosslinking.

The piezoelectricity of collagen is purported to be linked to many biological processes including bone formation and wound healing. Although the piezoelectricity of tissue-derived collagen has been documented across the length scales, little work has been undertaken to characterise the local electromechanical properties of processed collagen, which is used as a base for tissue-engineering implants. In this work, three chemically distinct treatments used to form structurally and mechanically stable scaffolds-EDC-NHS, genipin and tissue transglutaminase-are investigated for their effect on collagen piezolectricity. Crosslinking with EDC-NHS is noted to produce a distinct self-assembly of the fibres into bundles roughly 300 nm in width regardless of the collagen origin. These fibre bundles also show a localised piezoelectric response, with enhanced vertical piezoelectricity of collagen. Such topographical features are not observed with the other two chemical treatments, although the shear piezoelectric response is significantly enhanced upon crosslinking. These observations are reconciled by a proposed effect of the crosslinking mechanisms on the molecular and nanostructure of collagen. These results highlight the ability to modify the electromechanical properties of collagen using chemical crosslinking methods.

An Unusual Presentation of Osteochondroma on the Dorsal Surface of the Scapula: A Review of Two Patients.

INTRODUCTION: Osteochondroma of the scapula is a rare tumour of the thorax. It constitutes 14.4% of all tumours of the scapula with the ventral surface being the most common site of presentation. The dorsal surface of the scapula is rarely seen as a potential site for the origin of osteochondroma from our review of the literature, which was the case in our patient. Most of the patients presenting with osteochondroma on the dorsal aspect of scapula have been reported to be of the sessile variant. CASE REPORT: We report two rare cases of a pedunculated variety of osteochondroma at an unusual site-dorsal surface of the scapula in a 19-year-old male and a 5-year-old male child. The tumours were excised and the diagnosis was confirmed by histopathological studies. CONCLUSION: This case series is reported for its rarity and its unusual site of presentation. A solitary congenital variant of osteochondroma of the scapula has never been reported to the best of our knowledge.