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Tumors were characterized as nonhealing wounds by Virchow in 1858 and Dvorak in 1986. Since then, researchers have analyzed tumors from a new perspective. The parallels between tumorigenesis and physiological wound healing can provide a new framework for developing antitumor therapeutics. One commonality between tumors and wounds is the involvement of the stromal environment, particularly adipose stromal/stem cells (ASCs). ASCs exhibit dual functions, in which they stimulate tumor progression and assist in tissue repair and regeneration. Numerous studies have focused on the role of ASCs in cancer and wound healing, but none to date has linked age, cancer, and wound healing. Furthermore, very few studies have focused on the role of donor-specific characteristics of ASCs, such as age and their role in facilitating ASC behavior in cancer and wound healing. This review article is designed to provide important insights into the impact of donor age on ASC tumor and wound response and their role in facilitating ASC behavior in cancer and wound healing.

Sperm motility analysis of aquatic model species is important yet challenging due to the small sample volume, the necessity to activate with water, and the short duration of motility. To achieve standardization of sperm activation, microfluidic mixers have shown improved reproducibility over activation by hand, but challenges remain in optimizing and simplifying the use of these microdevices for greater adoption. The device described herein incorporates a novel micromixer geometry that aligns two sperm inlet streams with modified herringbone structures that split and recombine the sample at a 1:6 dilution with water to achieve rapid and consistent initiation of motility. The polydimethylsiloxane (PDMS) chip can be operated in a positive or negative pressure configuration, allowing a simple micropipettor to draw samples into the chip and rapidly stop the flow. The device was optimized to not only activate zebrafish sperm but also enables practical use with standard computer-assisted sperm analysis (CASA) systems. The micromixer geometry could be modified for other aquatic species with differing cell sizes and adopted for an open hardware approach using 3D resin printing where users could revise, fabricate, and share designs to improve standardization and reproducibility across laboratories and repositories.

Worldwide use and disposal of plastics have reached a dramatic saturation point, polluting lands, oceans, and air across the globe. Responding to such a challenge requires, among other environmental remediation measures, the manufacture of alternative sustainable plastics. Recent studies in the area have enabled the development of degradable plastics; however, the rate and conditions required for the degradation of such materials remains under scrutiny. Here, we introduce a new class of fully plant-based, rapidly degradable lignin and zein composite blend that can be transformed into macroscopic structures using extrusion three-dimensional (3D) printing. Corn-derived zein forms the polymeric solution, while insoluble lignin granules act as a binder for enhanced printability and facile degradation. The blend showcases a shear-thinning behavior that is ideal for rapid extrusion printing into desired 3D structures, from cuvette caps to circuit boards. Biodegradation studies show that common bacteria readily found in soil and compost are able to decompose structures made with the lignin–zein composite in shorter time frames compared to a known biodegradable plastic, viz., polylactic acid. The rapid biodegradability and enhanced processability highlight the potential of lignin–zein composites to decrease our dependence on petroleum oil-based plastics.

The application of engineered biomaterials for wound healing has been pursued since the beginning of tissue engineering. Here, we attempt to apply functionalized lignin to confer antioxidation to the extracellular microenvironments of wounds and to deliver oxygen from the dissociation of calcium peroxide for enhanced vascularization and healing responses without eliciting inflammatory responses. Elemental analysis showed 17 times higher quantity of calcium in the oxygen releasing nanoparticles. Lignin composites including the oxygen releasing nanoparticles released around 500 ppm oxygen per day at least for 7 days. By modulating the concentration of the methacrylated gelatin, we were able to maintain the injectability of lignin composite precursors and the stiffness of lignin composites suitable for wound healing after photo-crosslinking.In situformation of lignin composites with the oxygen releasing nanoparticles enhanced the rate of tissue granulation, the formation of blood vessels and the infiltration of α-smooth muscle actin+fibroblasts into the wounds over 7 days. At 30 days after surgery, the lignin composite with oxygen generating nanoparticles remodeled the collagen architecture resembling to the reticular pattern of unwounded collagen with minimal scar formation. Thus, our study shows the potential of functionalized lignin for wound healing applications requiring balanced antioxidation and controlled release of oxygen for enhanced tissue granulation, vascularization and maturation of collagens.

Three-dimensional matrices of collagen type I (Col I) are widely used in tissue engineering applications for its abundance in many tissues, bioactivity with many cell types, and excellent biocompatibility. Inspired by the structural role of lignin in a plant tissue, we found that sodium lignosulfonate (SLS) and an alkali-extracted lignin from switchgrass (SG) increased the stiffness of Col I gels. SLS and SG enhanced the stiffness of Col I gels from 52 to 670 Pa and 52 to 320 Pa, respectively, and attenuated shear-thinning properties, with the formulation of 1.8 mg/mL Col I and 5.0 mg/mL SLS or SG. In 2D cultures, the cytotoxicity of collagen-SLS to adipose-derived stromal cells was not observed and the cell viability was maintained over 7 days in 3D cultures. Collagen-SLS composites did not elicit immunogenicity when compared to SLS-only groups. Our collagen-SLS composites present a case that exploits lignins as an enhancer of mechanical properties of Col I without adverse cytotoxicity and immunogenicity for

The use of 3-dimensional (3-D) printing is gaining popularity in life sciences and driving innovation in fields including aquatic sperm cryopreservation. Yet, little is known about the effects leachates from these objects may have on biological systems. In this study, we investigated if exposure to leachates from 3-D printed objects fabricated from different photo-curable resins could affect sperm quality in two model fish species, zebrafish (Danio rerio) and goldfish (Carassius auratus). Leachates were collected following contact periods of 10 min and 22 h with objects manufactured using a mask LCD resin printer and three different commercially available resins (i.e., standard, eco-friendly, and impact-resistant). Sperm cells were exposed to the leachates for 18 min, and parameters related to sperm motility, cell count, and membrane integrity were evaluated. All experiments were blinded. Leachate originating from contact with impact-resistant resin for 10 min significantly reduced the cell count of zebrafish sperm, while leachate originating from contact with standard resin for 22 h significantly increased the beat cross frequency of goldfish sperm. The changes were not observed across species and no adverse effects were recorded in percent motility, velocity, amplitude of lateral head movement, or membrane integrity of sperm. Our findings demonstrate that exposure to leachates from certain 3-D printed resins can affect sperm quality, while other resins may support sperm quality evaluation. Further investigations are warranted to assess other parameters, effects, and their biological relevance for a variety of aquatic species.

Genetic resources of aquatic species are of tremendous value, but worldwide these are maintained almost exclusively as live populations. This is extremely expensive and insecure, and largely results from a pervasive lack of production capability, quality management, and reproducibility in cryopreservation that are barriers in development of germplasm repositories. Community-based technology approaches are emerging that can stimulate research previously limited by a lack of affordable, customizable equipment. Open-access technologies can provide for custom design and fabrication not available through traditional manufacturing. This can assist repository development with robust sample production methods and strong quality management, and can greatly improve reproducibility and standardization. Open technologies can support establishment of new communities of users, makers, and developers that collectively strive to develop open hardware in a distributed (i.e., non-centralized) fashion that can yield aggregate throughput. This occurs through use of consumer-level tools, supplies, software, and equipment, free exchange of designs and modifications, and a shared sense of mission. For cryopreservation and repository development, we have identified 14 categories of open hardware for a processing pathway, and six categories for a quality management pathway. Open hardware offers economic incentives to develop repositories for aquatic species, something that has not occurred despite 70 years of research largely focused on protocol development rather than practical applications. Advanced development of custom scientific hardware enhancing open technologies will be facilitated by interdisciplinary collaboration across biological and engineering fields. This manuscript is a contribution to the Special Issue in memory of Dr. Duane Garner, a leader in the sperm biology.

Experiments were conducted to establish the phase diagrams for ternary systems containing (acetic acid or propionic acid or butyric acid + water + alcohol ethoxylate surfactant) at 308.15 K and ambient pressure. Results indicated that the systems belong to Type 1 Treybal classification with water–surfactant binary pair exhibiting partial miscibility. The liquid–liquid equilibrium data were used to determine the ability of the surfactant to extract the acids from aqueous solutions. The calculated distribution coefficients and separation factors indicated that the effectiveness of the surfactant to extract acids follow the trend: butyric acid > propionic acid > acetic acid. The effectiveness of the surfactant to extract butyric acid from aqueous solutions is similar to previously studied environmentally-friendly solvents with added benefit of being non-inhibitory to microbial growth and metabolism. These characteristics of the alcohol ethoxylate used in this study could be exploited for the development of an extractive butyric acid fermentation process.

Hydroxyapatite (HA)-coated metals are biocompatible composites, which have potential for various applications for bone replacement and regeneration in the human body. In this study, we proposed the design of biocompatible, flexible composite implants by using a metal mesh as substrate and HA coating as bone regenerative stimulant derived from a simple sol-gel method. Experiments were performed to understand the effect of coating method (dip-coating and drop casting), substrate material (titanium and stainless steel) and substrate mesh characteristics (mesh size, weave pattern) on implant's performance. HA-coated samples were characterized by X-ray diffractometer, transmission electron microscope, field-emission scanning electron microscope, nanoindenter, polarization and electrochemical impedance spectroscopy, and biocompatibility test. Pure or biphasic nanorod HA coating was obtained on mesh substrates with thicknesses varying from 4.0 to 7.9 μm. Different coating procedures and number of layers did not affect crystal structure, shape, or most intense plane reflections of the HA coating. Moduli of elasticity below 18.5 GPa were reported for HA-coated samples, falling within the range of natural skull bone. Coated samples led to at least 90% cell viability and up to 99.5% extracellular matrix coverage into a 3-dimensional network (16.4% to 76.5% higher than bare substrates). Fluorescent imaging showed no antagonistic effect of the coatings on osteogenic differentiation. Finer mesh size enhanced coating coverage and adhesion, but a low number of HA layers was preferable to maintain open mesh areas promoting extracellular matrix formation. Finally, electrochemical behavior studies revealed that, although corrosion protection for HA-coated samples was generally higher than bare samples, galvanic corrosion occurred on some samples. Overall, the results indicated that while HA-coated titanium grade 1 showed the best performance as a potential implant, HA-coated stainless steel 316 with the finest mesh size constitutes an adequate, lower cost alternative.

Printing of polymeric composites into desired patterns and shapes has revolutionized small-scale manufacturing processes. However, high-resolution printing of adaptive materials that change shape in response to external stimuli remains a significant technical challenge. The article presents a new approach of printing thermoresponsive poly(N-isopropylacrylamide) into macroscopic structures that dynamically reconfigure in response to heating and cooling cycles. The printing process is performed using an external laser source, which enables thermal cross-linking of the polymer ink consisting of monomer, cross-linker, initiator, and inorganic nanoparticles. It is shown that the addition of silica nanoparticles enhances the mechanical properties of poly(N-isopropylacrylamide) while maintaining its thermoresponsiveness at micrometer-scale resolution, which otherwise is not feasible by extrusion-based three-dimensional printing techniques. It is demonstrated that spatial reconfiguration of the printed monolayers upon increasing temperature is governed by the local geometry, which enables mimicking the reconfiguration of plant leaves in a natural environment. The study lays a foundation for developing a new fabrication platform to print thermoresponsive structures that may find applications in biomedical implants, sensors, and other multi-responsive materials.