Biomedical Tissue Research Articles

Sainsc: A Computational Tool for Segmentation-Free Analysis of In Situ Capture Data.

Spatially resolved transcriptomics (SRT) has become the method of choice for characterising the complexity of biomedical tissue samples. Until recently, scientists were restricted to SRT methods that can profile a limited set of target genes at high spatial resolution or transcriptome-wide but at a low spatial resolution. Through recent developments, there are now methods that offer both subcellular spatial resolution and full transcriptome coverage. However, utilising these new methods' high spatial resolution and gene resolution remains elusive due to several factors, including low detection efficiency and high computational costs. Here, we present Sainsc (Segmentation-free analysis of in situ capture data), which combines a cell-segmentation-free approach with efficient data processing of transcriptome-wide nanometre-resolution spatial data. Sainsc can generate cell-type maps with accurate cell-type assignment at the nanometre scale, together with corresponding maps of the assignment scores that facilitate interpretation of the local confidence of cell-type assignment. We demonstrate its utility and accuracy for different tissues and technologies. Compared to other methods, Sainsc requires lower computational resources and has scalable performance, enabling interactive data exploration. Sainsc is compatible with common data analysis frameworks and is available as open-source software in multiple programming languages.

Optimizing extraction of collagen from hazardous leather shaving dusts by crude protease enzyme: Chrome recovery and reuse for leather rechroming

This study explores an eco-friendly method to achieve 99.98 % dechroming (reducing Cr from 7700 to 4.71 ppm) of Chrome-tanned leather shaving dust (CSD), through enzymatic hydrolysis using crude protease. The enzyme exhibited strong activity (>40 U mL−1) across a temperature range of 50 °C to 65 °C and a pH range of 5 to 11. The pH of the mixture containing CSD, water, MgO, and enzyme was maintained at 8.9 during hydrolysis. The temperature, hydrolysis time, and enzyme concentration were optimized using response surface methodology (RSM). Under optimal conditions of 17.57 % enzyme concentration, 62.01 °C, and a hydrolysis time of 7 h, the predicted collagen yield was 31.66 %. Laboratory experiments conducted with these predicted parameters resulted in a collagen recovery of 30.9 %, achieving an accuracy of 97.6 % compared to the predictions. In contrast, hydrolysis with MgO alone achieved only 87.01 % dechroming with about 2 % collagen yield, highlighting the enzyme's superior effectiveness. The enzymatic cleavage of peptide bonds in the leather matrix enhanced collagen solubilization. Characterization techniques, including FT-IR, NMR, XRD, DSC, and TGA, confirmed successful extraction and purity, with the collagen being rich in glycine and proline. Cytotoxicity results demonstrated its non-toxic nature, indicating potential applications in biomedical fields, tissue engineering, food, pharmaceuticals, and cosmetics. The recovered chromium sulfate was reused for rechroming goat wet blue leather, with chrome content in crust leather treated with recovered basic chromium sulfate (rBCS) and fresh basic chromium sulfate (BCS) being 3.23 % and 3.35 %, respectively, both meeting industry standards for goat crust leather. SynopsisAn eco-friendly method for dechroming chrome-tanned leather shaving dust (CSD) and extracting collagen was established. The process achieved 99.98 % dechroming and 30.9 % collagen yield using crude protease enzyme. Characterization confirmed the collagen's purity, and recovered chromium sulfate was reused for rechroming goat leather, meeting industry standards.

Some Problems with the Legal Regulation of the Relations in the Field of Medical Tissue Technologies in the Russian Federation

This article substantiates the need for shaping a separate legal system to regulate the relations in tissue banking, as well as biomedical tissue and hybrid technologies. The key problems that have been faced by biomedical and cellular tissue technologies in Russia were analyzed. The major deficiencies and contradictions regarding organ and tissue transplantation in the current Russian legal system were pointed out. First, there have been no federal laws governing the activities of tissue banks. Second, the procedures of human biomaterial donation for medical use remain uncontrolled. Third, there has been no consistency in the retrieval, storage, and transportation of human biomaterials. Finally, the list and legal status of organizations engaged in relevant activities and the legal regime of biological material used for these purposes have not been defined. The study focuses on the practical problems of tissue banks and innovative biomedical technologies that require a legislative initiative. Possible ways to overcome the identified contradictions and problems were discussed.

Harnessing Peptide-Based Hydrogels for Enhanced Cartilage Tissue Engineering.

Cartilage tissue engineering remains a formidable challenge due to its complex, avascular structure and limited regenerative capacity. Traditional approaches, such as microfracture, autografts, and stem cell delivery, often fail to restore functional tissue adequately. Recently, there has been a surge in the exploration of new materials that mimic the extracellular microenvironment necessary to guide tissue regeneration. This review investigates the potential of peptide-based hydrogels as an innovative solution for cartilage regeneration. These hydrogels, formed via supramolecular self-assembly, exhibit excellent properties, including biocompatibility, ECM mimicry, and controlled biodegradation, making them highly suitable for cartilage tissue engineering. This review explains the structure of cartilage and the principles of supramolecular and peptide hydrogels. It also delves into their specific properties relevant to cartilage regeneration. Additionally, this review presents recent examples and a comparative analysis of various peptide-based hydrogels used for cartilage regeneration. The review also addresses the translational challenges of these materials, highlighting regulatory hurdles and the complexities of clinical application. This comprehensive investigation provides valuable insights for biomedical researchers, tissue engineers, and clinical professionals aiming to enhance cartilage repair methodologies.

Modifying Naturally Occurring, Nonmammalian-Sourced Biopolymers for Biomedical Applications.

Natural biopolymers have a rich history, with many uses across the fields of healthcare and medicine, including formulations for wound dressings, surgical implants, tissue culture substrates, and drug delivery vehicles. Yet, synthetic-based materials have been more successful in translation due to precise control and regulation achievable during manufacturing. However, there is a renewed interest in natural biopolymers, which offer a diverse landscape of architecture, sustainable sourcing, functional groups, and properties that synthetic counterparts cannot fully replicate as processing and sourcing of these materials has improved. Proteins and polysaccharides derived from various sources (crustaceans, plants, insects, etc.) are highlighted in this review. We discuss the common types of polysaccharide and protein biopolymers used in healthcare and medicine, highlighting methods and strategies to alter structures and intra- and interchain interactions to engineer specific functions, products, or materials. We focus on biopolymers obtained from natural, nonmammalian sources, including silk fibroins, alginates, chitosans, chitins, mucins, keratins, and resilins, while discussing strategies to improve upon their innate properties and sourcing standardization to expand their clinical uses and relevance. Emphasis will be placed on methods that preserve the structural integrity and native biological functions of the biopolymers and their makers. We will conclude by discussing the untapped potential of new technologies to manipulate native biopolymers while controlling their secondary and tertiary structures, offering a perspective on advancing biopolymer utility in novel applications within biomedical engineering, advanced manufacturing, and tissue engineering.

Qualitative and quantitative characterization of elastin-like polypeptides combining low-PH/low-temperature bottom-up and intact protein liquid chromatography mass spectrometric analysis.

Elastin-like polypeptides (ELPs) are elastic and thermoresponsive biopolymers composed of VPGXG repeats (X can be any amino acid except proline), used in biomedical applications, for example, tissue engineering and drug delivery. As different variants of ELP are mostly produced fermentatively, there is a need for the development of analysis methods that allow for absolute protein quantification in both complex matrices and purified samples and MW determination of the final products. ELPs were intracellularly expressed in Escherichia coli quantified after cell lysis and enzymatic digestion using a proline-specific protease ProAlanase (Promega) at acidic conditions. Resulting peptides were separated by liquid chromatography, and mass spectrometry analysis was conducted by electrospray ionization high-resolution mass spectrometry using an Orbitrap mass spectrometer. The addition of a stable isotopically labeled internal standard enabled quantification in complex matrices. Prior to intact mass analysis, ELPs were purified from fermentation broth by inverse temperature cycling. Intact protein analysis was performed using reversed-phase liquid chromatography, and mass spectrometry analysis was conducted by electrospray ionization high-resolution mass spectrometry using a time-of-flight mass spectrometer. Absolute quantification of ELPs was achieved by utilizing ELP-specific properties, that is, proline-rich, soluble at low pH and low temperature. The repetitive nature of ELPs allows for sensitivity increase and use of higher dilution factors to minimize the matrix effects. Despite the lack of amino acids with charged side chains (Arg, His, Lys, Asp, and Glu) in ELP, we demonstrated successful intact protein analysis using reversed-phase LC coupled to electrospray ionization TOF MS. Moreover, truncated protein forms could be chromatographically separated and characterized as well as N-terminal modifications. Both methods combined enabled quantitative and qualitative characterization of fermentatively produced ELPs.

Fabrication Methods, Structural, Surface Morphology and Biomedical Applications of MXene: A Review.

Recently, two-dimensional (2-D) layered materials have revealed outstanding properties and play a crucial role for numerous advanced applications. The emerging transition metal carbides and nitrides, known as MXene with empirical formula Mn+1XnTx, have generated widespread attention and demonstrated impressive potential in various fields. The fabrication of 2-D novel MXene and its composites and their characterizations are applicable to vast applications in different areas such as energy storage, gas sensors, catalysis, and biomedical applications. In this review, the main focus is on the various synthesis methods, their properties, and biomedical applications. This review provides detailed illustrations of MXenes for many biomedical applications, including bioimaging, drug delivery, therapies, biosensors, tissue engineering, and antibacterial reagents. The challenges and future prospects were highlighted in a comprehensive manner, and the existing problems and potential for MXene-based biomaterials were analyzed with the goal of accelerating their use in the biomedical field.

Research progress of electrospinning polyurethane fiber in the field of biomedical tissue engineering

Polyurethane materials have good biocompatibility, blood compatibility, mechanical properties, fatigue resistance and processability, and have always been highly valued as medical materials. Polyurethane fibers prepared by electrostatic spinning technology can better mimic the structure of natural extracellular matrices (ECMs), and seed cells can adhere and proliferate better to meet the requirements of tissue repair and reconstruction. The purpose of this review is to present the research progress of electrostatically spun polyurethane fibers in bone tissue engineering, skin tissue engineering, neural tissue engineering, vascular tissue engineering and cardiac tissue engineering, so that researchers can understand the practical applications of electrostatically spun polyurethane fibers in tissue engineering and regenerative medicine.

Expression, characterization, and application of human-like recombinant gelatin

Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen, belonging to natural biopeptides. With irreplaceable biological functions in the field of biomedical science and tissue engineering, it has been widely applied. The amino acid sequence of recombinant human-like gelatin was constructed through a newly designed hexamer composed of six protein monomer sequences in series, with the minimum repeating unit being the characteristic Gly-X-Y sequence found in type III human collagen α1 chain. The nucleotide sequence was subsequently inserted into the genome of Pichia pastoris to enable soluble secretion expression of recombinant gelatin. At the shake flask fermentation level, the yield of recombinant gelatin is up to 0.057 g/L, and its purity can rise up to 95% through affinity purification. It was confirmed in the molecular weight determination and amino acid analysis that the amino acid composition of the obtained recombinant gelatin is identical to that of the theoretically designed. Furthermore, scanning electron microscopy revealed that the freeze-dried recombinant gelatin hydrogel exhibited a porous structure. After culturing cells continuously within these gelatin microspheres for two days followed by fluorescence staining and observation through confocal laser scanning microscopy, it was observed that cells clustered together within the gelatin matrix, exhibiting three-dimensional growth characteristics while maintaining good viability. This research presents promising prospects for developing recombinant gelatin as a biomedical material.

Employing Metal-Enriched Polymeric Composites: An Innovative Approach for Combatting Microbes and Bacteria in Building Components in Public Places

The escalating occurrence of hospital-associated infections globally, compounded by the ongoing pandemic, has spurred researchers to delve into innovative approaches for combating pathogens and overcoming their resistance to commonly used materials. One of the most important concerns is frequently touched building components in public places and hospitals, which serve as potential sources of infection transmission, prompting a pressing need for effective antimicrobial solutions. This research developed antimicrobial polymeric composites comprising Copper (Cu), Aluminum (Al), and Stainless Steel (SS) particles incorporated into Polylactic Acid (PLA) via injection molding as a commercial method for the production of building components, to investigate the antimicrobial properties. The study aims at increasing the antimicrobial efficiency of polymeric composites with different metallic particles and tests the prepared polymeric composites (two sets of Cu-enriched composites, i.e., Cu–PLA–SS, by mixing Al–PLA with Cu–PLA, and Cu–PLA–Al, by mixing SS–PLA with Cu–PLA) against various bacteria. The results demonstrate that the samples prepared with Cu-PLA mixed with SS and Al exhibited the best antibacterial activity (98.6%) after 20 min of exposure to all bacteria, notably against Staphylococcus aureus and Enterococci. In addition, the hybrid composites Cu–PLA–SS and Cu–PLA–Al, prepared using injection molding, showed similar antimicrobial activity against all bacteria compared to those prepared using 3D printing. Therefore, polymeric composites enriched with metallic particles such as Cu, Al, and SS prepared via injection molding show potential in biomedical applications, food packaging, tissue engineering, and various technological industries, offering viable solutions for environments where risks from contact with infected surfaces are a concern.

Highly controlled multiplex electrospinning

Applications of electrospinning (ES) range from fabrication of biomedical devices and tissue regeneration scaffolds to light manipulation and energy conversion, and even to deposition of materials that act as growth platforms for nanoscale catalysis. One major limitation to wide adoption of ES is stochastic fiber deposition resulting from the chaotic motion of the polymer stream as is approaches the deposition surface. In the past, fabrication of structures or materials with precisely determined mesoscale morphology has been accomplished through modification of electrode shape, use of multi-dimensional electrodes or pins, deposition onto weaving looms, hand-held electrospinning devices that allow the user to guide deposition, or electric field manipulation by lensing elements or apertures. In this work, we demonstrate an ES system that contains multiple high voltage power supplies that are independently controlled through a control algorithm implemented in LabVIEW. The end result is what we term “multiplex ES” where multiple independently controlled high-voltage signals are combined by the ES fiber to result in unique deposition control. COMSOL Multiphysics® software was used to model the electric field produced in this novel ES system. Using the multi-power supply system, we demonstrate fabrication of woven fiber materials that do not require complex deposition surfaces. Time-varied sinusoidal wave inputs were used to create electrospun torus shapes. The outer diameter of the tori was found, through parametric analysis, to be rather insensitive to frequency used during deposition, while inner diameter was inversely related to frequency, resulting in overall width of the tori increasing with frequency. Multiplex ES has a high-frequency cutoff based on the time response of the high voltage electrical circuit. These time constants were measured and minimized through the addition of parallel resistors that decreased impedance of the system and improved the high-frequency cutoff by up to 63%.

Tuning the rheological properties of chitosan/alginate hydrogels for tissue engineering application

Biomaterials that mimic biological tissues are in great demand in tissue engineering. Hydrogels are rising as a conducive candidate in tissue engineering on account of their water-holding capacity, mechanical strength, and elasticity. Nevertheless, the development of hydrogels that mimic biological tissues with the desired stability and mechanical strength, remains a notable barrier. In this investigation, chitosan/alginate hydrogels were prepared by tuning the chitosan concentration from 0.5 % to 2.5 %w/v with a fixed 1 %w/v alginate concentration using 0.1 % glutaraldehyde as a gelling agent. The hydrogel system forms through covalent bonding between chitosan and alginate, mediated by aldehyde groups of the glutaraldehyde. The mechanical strength of the hydrogel was elucidated by probing its viscoelastic behavior through rheological analysis. The rheological investigations revealed that the prepared chitosan/alginate hydrogels are profoundly stable with shear-thinning characteristics. The increase in chitosan concentration enhanced the stability and viscoelastic attributes of the hydrogels. The yield stress values ranging from 0.93 kPa to 14.24 kPa indicate the possibility of using these hydrogels in bioadhesives and soft and bone tissue engineering. The complex modulus of the prepared chitosan/alginate hydrogels resembles the shear modulus of liver tissues, osteogenic cells, and articular cartilage, and hence, these hydrogels pose as suitable candidates in liver, bone, and cartilage tissue engineering. The chitosan/alginate hydrogels possess outstanding self-healing ability, along with biocompatibility, stability, and mechanical strength, rendering them highly advantageous for applications in biomedical tissue engineering and bioadhesives.

Time-domain full-field optical coherence tomography with a digital defocus correction.

Time-domain full-field optical coherence tomography (TD-FF-OCT) is an interferometric technique capable of acquiring high-resolution images deep within the biomedical tissue, utilizing a spatially and temporally incoherent light source. However, optical aberrations, such as sample defocus, can degrade the image quality, thereby limiting the achievable imaging depth. Here we demonstrate that the sample defocus within a highly scattering medium can be digitally corrected over a wide defocus range if the optical path lengths in the sample and reference arms are matched. We showcase the application of digital defocus correction on both reflective and scattering samples, effectively compensating digitally for up to 1 mm of defocus.

Factors Affecting the Evaluation of Collagen Deposition and Fibrosis In Vitro.

Immune responses to biomedical implants, wound healing, and diseased tissues often involve collagen deposition by fibroblasts and other stromal cells. Dysregulated collagen deposition can lead to complications, such as biomaterial fibrosis, cardiac fibrosis, desmoplasia, liver fibrosis, and pulmonary fibrosis, which can ultimately result in losses of organ function or failure of biomedical implants. Current in vitro methods to induce collagen deposition include growing the cells under macromolecular crowding conditions or on fibronectin-coated surfaces. However, the majority of these methods have been demonstrated with a single cell line, and the combined impacts of culture conditions and postculture processing on collagen deposition have not been explored in detail. In this work, the effects of macromolecular crowding versus fibronectin coating, fixation with methanol versus fixation with paraformaldehyde, and use of plastic substrates versus glass substrates were evaluated using the WI-38 human lung fibroblast cell line. Fibronectin coating was found to provide enhanced collagen deposition under macromolecular crowding conditions, while a higher plating density led to improved collagen I deposition compared with macromolecular crowding. Collagen deposition was found to be more apparent on plastic substrates than on glass substrates. The effects of primary cells versus cell lines, and mouse cells versus human cells, were evaluated using WI-38 cells, primary human lung fibroblasts, primary human dermal fibroblasts, primary mouse lung fibroblasts, primary mouse dermal fibroblasts, and the L929 mouse fibroblast cell line. Cell lines exhibited enhanced collagen I deposition compared with primary cells. Furthermore, collagen deposition was quantified with picrosirius red staining, and plate-based drug screening through picrosirius red staining of decellularized extracellular matrices was demonstrated. The results of this study provide detailed conditions under which collagen deposition can be induced in vitro in multiple cell types, with applications including material development, development of potential antifibrotic therapies, and mechanistic investigation of disease pathways. Impact Statement This study demonstrated the effects of cell type, biological conditions, fixative, culture substrate, and staining method on in vitro collagen deposition and visualization. Further the utility of plate-based picrosirius red staining of decellularized extracellular matrices for drug screening through collagen quantification was demonstrated. These results should provide clarity and a path forward for researchers who aim to conduct in vitro experiments on collagen deposition.

Three-Dimensional Printing Strategies for Enhanced Hydrogel Applications.

This study explores the dynamic field of 3D-printed hydrogels, emphasizing advancements and challenges in customization, fabrication, and functionalization for applications in biomedical engineering, soft robotics, and tissue engineering. It delves into the significance of tailored biomedical scaffolds for tissue regeneration, the enhancement in bioinks for realistic tissue replication, and the development of bioinspired actuators. Additionally, this paper addresses fabrication issues in soft robotics, aiming to mimic biological structures through high-resolution, multimaterial printing. In tissue engineering, it highlights efforts to create environments conducive to cell migration and functional tissue development. This research also extends to drug delivery systems, focusing on controlled release and biocompatibility, and examines the integration of hydrogels with electronic components for bioelectronic applications. The interdisciplinary nature of these efforts highlights a commitment to overcoming material limitations and optimizing fabrication techniques to realize the full potential of 3D-printed hydrogels in improving health and well-being.

Progress in the design principle of biomedical tissue adhesive hydrogel with naturally derived substance

AbstractIn recent years, natural substance‐based tissue adhesive hydrogels have been widely studied by researchers because of their practicability and affordability. In this review, we summarized the design principles and mechanisms for constructing natural substance‐based tissue adhesive hydrogels from the perspective of polyphenols (catechol, dopamine, tannic acid), cationic polymers (chitosan, lysine, cationic antibacterial peptides), polysaccharides and other natural substances. In addition, according to the morphology and size of tissue adhesive hydrogels, it was divided into macroscopic hydrogels and microscopic hydrogels. Therefore, the natural substance‐based adhesive macroscopic hydrogels such as injectable hydrogels and hydrogel patches and natural substance‐based adhesive microscopic hydrogels including hydrogel microspheres were reviewed. Furthermore, we summarized the review and provided outlook based on the present tissue adhesive hydrogels. The review aimed to summarize the progress in natural substance‐based tissue adhesive hydrogels and provide a valuable reference for the development of tissue adhesive hydrogels and its applications in biomedical field.

Tumor tissue samples collection for scientific research in morphology and molecular oncology

Purpose of the study. Is to describe the experience of creating a collection of biological images of tumor tissues and biomaterials, which are control samples, for scientific research in morphology and molecular oncology.Materials and methods. We studied the molecular markers of cell cycle regulation, apoptosis, oncogenesis and angiogenesis, the expression of proteins that regulate inflammation and tumor infiltrate cells in biocollections of verified tumors of common localizations: e. g. thyroid cancer, colorectal cancer, breast cancer, prostate adenocarcinoma, endometrioid adenocarcinoma. Also, tissue fragments with normal structure or non-tumor pathology (autoimmune thyroiditis, adenomatous and thyrotoxic goiter, benign formations of the colon, fibrocystic disease of the mammary glands, benign prostatic hyperplasia, endometrial hyperplasia) were used as control samples or comparison groups. The total number of tissue samples is n = 7000.Results. It is reasonable to gather the collection in a pathomorphological laboratory according to the profile of the medical institutions, which has a sufficient volume of incoming target material and specialized morphologists to verify tumors of a given localization. It is necessary to consider the regional and ethnic specifics of the population, which determines the sampling and mutational load. The laboratory must initiate an addition to the informed consent of patients about the possibility of conducting morphological and molecular genetic studies for scientific purposes and publishing their results in a depersonalized form for the development of new elaborations, when signing the contracts with legal entities and individuals and when serving patients within an institution. When working with biocollections, it has to consider having registers of tissue biomaterials of target disorder groups of main localizations with downloading by year from an accessible information system, consider external factors affecting the database (changes in clinical recommendations and classifications, the population of patients served, pandemics and other significant events). The standard of the preanalytical stage, data collection, development of protocols for analytical molecular genetic studies and their evaluation, the utilization of the capabilities of working with reagents for scientific tasks and modeling experiments on laboratory animals are crucial.Conclusion. The formed biocollection made it possible to carry out a number of initiative and funded domestic and international scientific projects at the request of clinicians and fundamental researchers, as well as to improve the quality standards of morphological and molecular genetic oncology diagnostics. Biobanking makes the pathological archive more accessible for review and use, significantly expanding its scientific and practical potential. Scientific and medical research do not conflict and can be used within the same laboratory.

Biomimetic-Membrane-Protected Plasmonic Nanostructures as Dual-Modality Contrast Agents for Correlated Surface-Enhanced Raman Scattering and Photoacoustic Detection of Hidden Tumor Lesions.

Optical imaging and spectroscopic modalities are of considerable current interest for in vivo cancer detection and image-guided surgery, but the turbid or scattering nature of biomedical tissues has severely limited their abilities to detect buried or occluded tumor lesions. Here we report the development of a dual-modality plasmonic nanostructure based on colloidal gold nanostars (AuNSs) for simultaneous surface-enhanced Raman scattering (SERS) and photoacoustic (PA) detection of tumor phantoms embedded (hidden) in ex vivo animal tissues. By using red blood cell membranes as a naturally derived biomimetic coating, we show that this class of dual-modality contrast agents can provide both Raman spectroscopic and PA signals for the detection and differentiation of hidden solid tumors with greatly improved depths of tissue penetration. Compared to previous polymer-coated AuNSs, the biomimetic coatings are also able to minimize protein adsorption and cellular uptake when exposed to human plasma without compromising their SERS or PA signals. We further show that tumor-targeting peptides (such as cyclic RGD) can be noncovalently inserted for targeting the ανβ3-integrin receptors expressed on metastatic cancer cells and tracked via both SERS and PA imaging (PAI). Finally, we demonstrate image-guided resections of tumor-mimicking phantoms comprising metastatic tumor cells buried under layers of skin and fat tissues (6 mm in thickness). Specifically, PAI was used to determine the precise tumor location, while SERS spectroscopic signals were used for tumor identification and differentiation. This work opens the possibility of using these biomimetic dual-modality nanoparticles with superior signal and biological stability for intraoperative cancer detection and resection.

The 3D-McMap Guidelines: Three-Dimensional Multicomposite Microsphere Adaptive Printing.

Microspheres, synthesized from diverse natural or synthetic polymers, are readily utilized in biomedical tissue engineering to improve the healing of various tissues. Their ability to encapsulate growth factors, therapeutics, and natural biomolecules, which can aid tissue regeneration, makes microspheres invaluable for future clinical therapies. While microsphere-supplemented scaffolds have been investigated, a pure microsphere scaffold with an optimized architecture has been challenging to create via 3D printing methods due to issues that prevent consistent deposition of microsphere-based materials and their ability to maintain the shape of the 3D-printed structure. Utilizing the extrusion printing process, we established a methodology that not only allows the creation of large microsphere scaffolds but also multicomposite matrices into which cells, growth factors, and therapeutics encapsulated in microspheres can be directly deposited during the printing process. Our 3D-McMap method provides some critical guidelines for issues with scaffold shape fidelity during and after printing. Carefully timed breaks, minuscule drying steps, and adjustments to extrusion parameters generated an evenly layered large microsphere scaffold that retained its internal architecture. Such scaffolds are superior to other microsphere-containing scaffolds, as they can release biomolecules in a highly controlled spatiotemporal manner. This capability permits us to study cell responses to the delivered signals to develop scaffolds that precisely modulate new tissue formation.

Bimodal DNA self-origami material with nucleic acid function enhancement

BackgroundThe design of DNA materials with specific nanostructures for biomedical tissue engineering applications remains a challenge. High-dimensional DNA nanomaterials are difficult to prepare and are unstable; moreover, their synthesis relies on heavy metal ions. Herein, we developed a bimodal DNA self-origami material with good biocompatibility and differing functions using a simple synthesis method. We simulated and characterized this material using a combination of oxDNA, freeze–fracture electron microscopy, and atomic force microscopy. Subsequently, we optimized the synthesis procedure to fix the morphology of this material.ResultsUsing molecular dynamics simulation, we found that the bimodal DNA self-origami material exhibited properties of spontaneous stretching and curling and could be fixed in a single morphology via synthesis control. The application of different functional nucleic acids enabled the achievement of various biological functions, and the performance of functional nucleic acids was significantly enhanced in the material. Consequently, leveraging the various functional nucleic acids enhanced by this material will facilitate the attainment of diverse biological functions.ConclusionThe developed design can comprehensively reveal the morphology and dynamics of DNA materials. We thus report a novel strategy for the construction of high-dimensional DNA materials and the application of functional nucleic acid–enhancing materials.Graphical