Biological Stimuli Research Articles

New Smart Antimicrobial Hydrogels, Nanomaterials, and Coatings: Earlier Action, More Specific, Better Dosing?

To fight against antibiotic-resistant bacteria adhering and developing on medical devices, which is a growing problem worldwide, researchers are currently developing new "smart" materials and coatings. They consist in delivery of antimicrobial agents in an intelligent way, i.e., only when bacteria are present. This requires the use of new and sophisticated tools combining antimicrobial agents with lipids or polymers, synthetic and/or natural. In this review, three classes of innovative materials are described: hydrogels, nanomaterials, and thin films. Moreover, smart antibacterial materials can be classified into two groups depending on the origin of the stimulus used: those that respond to a nonbiological stimulus (light, temperature, electric and magnetic fields) and those that respond to a biological stimulus related to the presence of bacteria, such as changes in pH or bacterial enzyme secretion. The bacteria presence can induce a pH change that constitutes a first potential biological trigger allowing the system to become active. A second biological trigger signal consists in enzymes produced by bacteria themselves. A complete panel of recent studies will be given focusing on the design of such innovative smart materials that are sensitive to biological triggers.

L-Arginine-Nitric Oxide-Asymmetric Dimethylarginine Pathway and the Coronary Circulation: Translation of Basic Science Results to Clinical Practice

By 1980, it was thought that we already knew most of the major mechanisms regulating vascular tone. However, after the somewhat serendipity discovery that endothelium is involved in mediation of relaxation to acetylcholine, a whole new world opened up and we had to rewrite our concept regarding vascular function and its regulation (not to mention many other fields). The new player was an endothelium derived relaxing factor, which molecular constitution has been identified to be nitric oxide (NO). This review summarizes the major molecular steps concerning how NO is synthetized from L-arginine. Also, the fate of L-arginine is described via the arginase and methylation pathways; both of them are affecting substantially the level and efficacy of NO. In vitro and in vivo effects of L-arginine are summarized and controversial clinical findings are discussed. On the basis of the use of methylated L-arginines, the vasomotor effects of endothelial NO released to agonists and increases in flow/wall shear stress (a major biological stimulus) is summarized. In this review the role of NO in the regulation of coronary vascular resistance, hence blood flow, is delineated and the somewhat questionable clinical use of NO donors is discussed. We made an attempt to summarize the biosynthesis, role, and molecular mechanisms of endogenously produced methylated L-arginine, asymmetric dimethylarginine (ADMA) in modulating vascular resistance, affecting the function of the heart. Additionally, the relationship between ADMA level and various cardiovascular diseases is described, such as atherosclerosis, coronary artery disease (CAD), ischemia/reperfusion injuries, and different types of coronary revascularization. A novel aspect of coronary vasomotor regulation is identified in which the pericardial fluid ADMA and endothelin play putative roles. Finally, some of the open possibilities for future research on L-arginine-NO-ADMA signaling are highlighted.

Substratum selection and feeding responses influence the demography of the sessile rotifer Cupelopagis vorax (Collothecacea: Atrochidae)

AbstractLarvae of the sessile rotifer Cupelopagis vorax swim using their ciliated corona, but do not feed. Once they attach to a substratum and metamorphose into adults, they are predatory on protozoans and micrometazoans. Here we present information on ingestion time, feeding behaviour and food preference of C. vorax using protozoans and non‐sessile rotifers as prey. We also tested effects of physical, chemical and biological stimuli on settlement of C. vorax larvae and, using life table experiments, determined their survivorship and fecundity on three, free‐floating macrophytes. Ingestion time was shortest on prey species smaller than 100 µm. Capture/attack ratio was low for Brachionus calyciflorus, but high for Lecane inermis and Peranema sp. The ingestion/capture ratio was lowest for Oxytricha sp. and highest for Euchlanis lyra and Squatinella lamellaris. Species that swim slowly and close to the surface of hydrophytes (E. lyra, Lepadella patella, L. inermis, Peranema sp., Philodina sp. and S. lamellaris) had lower ingestion time, higher encounter/attack ratio, and were the preferred prey in selectivity experiments. Larval settlement was higher on macrophyte leaves of Ceratophyllum demersum, Lemna valdiviana and Wolffiella sp., but lower on Azolla filiculoides and Wolffia columbiana. Coverslips coated with dried extracts of macrophytes showed lower rates of larval settlement compared to live macrophytes, as well as coverslips that had been allowed to develop natural biofilms or were physically roughened. Contrary to what might be expected from the settling tests, life‐table experiments showed that W. columbiana enhanced survivorship (mean lifespan and life expectancy) and rate of population increase, while animals attached to Wolffiella sp. had lower values for life history characteristics. This study adds to our understanding of the impact of Cupelopagis predation on protozoans and rotifers and the importance of substratum selection on larval settlement, adult survival, and reproductive potential after larval settlement.

Evaluation on redox-triggered degradation of thioether-bridged hybrid mesoporous organosilica nanoparticles

Incorporation of degradable groups such as thioether bonds can make nanoparticles susceptible to be degraded by biological redox stimulus. Few studies have paid attention to effects of different surface properties of carriers on degradation behaviors between traditional mesoporous silica carriers and hybrid organosilica carriers, caused by inserted thioether groups. In this work, colloidal mesoporous silica (CMS) and hybrid colloidal mesoporous silica (HCMS) with different contents of doped thioether bonds are constructed to compare their physicochemical properties and degradability. With the increased amounts of doped thioether bonds, specific surface areas and Zeta potentials of HCMS nanoparticles decrease. Additionally, dynamic contact angle and the oil-water distribution coefficient are combined to characterize the hydrophobicity of CMS and HCMS nanoparticles. Therefore, after incorporating thioether bonds into the structure of carriers, the degradation behavior of HCMS nanoparticles in the medium were the result of weighing the advantages of degradable thioether bonds and disadvantages of decreased specific surface area and enhanced hydrophobicity of carriers. Experimental results displayed that, in the high concentration of reductive environment, HCMS carriers with doping proper proportion of thioether groups showed the fast degradation rate due to the cleaved thioether bonds as the dominant factor. The present work breaks the common views that all thioether bonds-bridged organosilica could become excellent biodegradable carriers, providing an objective perspective to evaluate the degradability of hybrid organosilica carriers.

The Regulation of Exosome-Derived miRNA on Heterogeneity of Macrophages in Atherosclerotic Plaques.

Exosomes are nanosized vesicles secreted by most cells, which can deliver a variety of functional lipids, proteins, and RNAs into the target cells to participate in complex intercellular communications. Cells respond to certain physical, chemical, and biological stimuli by releasing exosomes. Exosomes are rich in small molecules of RNA, including miRNAs and mRNAs, which have been demonstrated to have certain functions in recipient cells. Recent studies on single-cell RNA sequences have revealed the transcription and the heterogeneity of macrophages in Ldlr-/-mice fed with a high-fat diet. Five macrophage populations were found in the atherosclerotic plaques. It is worth noting that these subset populations of macrophages seem to be endowed with different functions in lipid metabolism and catabolism. A total of 100 differentially expressed mRNAs were selected for these subset populations. Importantly, these macrophage populations were also present in human advanced atherosclerosis. To clarify the specific functions and the regulatory mechanism of these macrophage populations, we extracted exosome RNAs from the plasma of patients with chronic coronary artery disease (CAD) and performed RNA sequencing analysis. Compared with the healthy control, a total of 14 miRNAs were significantly expressed in these patients. A total of 5,248 potential mRNAs were predicted by the bioinformatics platform. Next, we determined the outcome of the intersection of these predicted mRNAs with 100 mRNAs expressed in the above-mentioned five macrophage populations. Based on the screening of miRNA–mRNA pairs, a co-expression network was drawn to find out the key RNAs. Three down-regulated miRNAs and five up-regulated mRNAs were selected for validation by real-time RT-PCR. The results showed that the expression of miR-4498 in plasma exosomes was lower than that in the healthy control, and the expressions of Ctss, Ccr2 and Trem2 mRNA in peripheral blood mononuclear cells isolated from CAD patients were higher. In order to clarify the regulatory mechanism, we established a co-culture system in vitro. Studies have shown that the uptake of exosomes from CAD patients can up-regulate the expression of Ctss, Trem2, and Ccr2 mRNA in THP-1 cells induced by lipopolysaccharide. Our findings revealed a unique relationship between the transcriptional signature and the phenotypic heterogeneity of macrophage in the atherosclerotic microenvironment.

3028 – ENHANCING AGED HEMATOPOIETIC STEM CELL FUNCTION WITH PROSTAGLANDIN E2

Aging of human hematopoiesis is associated with increased frequency and clonality of hematopoietic stem cells (HSC), along with functional compromise and myeloid bias, and donor age is a significant variable in survival after HSC transplantation. No clinical methods exist to enhance aged HSC function, and little is known regarding how aging affects molecular responses of HSC to biological stimuli. Exposure of young fish, mouse, nonhuman primate and human HSC to 16,16-dimethyl prostaglandin E2 (dmPGE2) can enhance transplantation, but the effect of dmPGE2 on aged HSC has not yet been tested. Bone marrow cells from young (3 mo) and aged (25 mo) C57BL/6J mice were pulsed ex vivo with dmPGE2 or vehicle prior to competitive transplantation. DmPGE2 enhanced long-term repopulation of aged grafts in primary and secondary transplantation, increasing final chimerism an average of 27%, similar to the average increase of 21% for young grafts (both p<0.05). RNA sequencing of highly purified HSC sorted after dmPGE2 pulse indicated CREB1, an established mediator of PGE2 signaling, remained the most activated regulator in both young and aged HSC, suggesting the major molecular responses to dmPGE2 are similar in young and old. A subset of genes differentially affected by dmPGE2 in young and old HSC included numerous phosphoproteins induced in young but already elevated with age. However, the highest-scoring cellular functions of dmPGE2-induced genes remained the same in young and aged HSC, including increased cell survival, homeostasis, synthesis of D-glucose, cell movement, self-renewal, differentiation, and decreased apoptosis. HSC expression of the PGE2 receptor EP4, implicated in HSC function, increased with age in both mRNA and surface protein. This work suggests that aging does not alter the major dmPGE2 response pathways in HSC, and dmPGE2 is able to enhance aged HSC function.

Role of Thermolysin in Catalytic-Controlled Self-Assembly of Fmoc-Dipeptides

In recent years, short peptide self-assembled materials, prepared under the control of the thermolysin catalyst, have been investigated extensively and shown to acquire various morphologies and fun...

Dioxin exposure and sexual dimorphism of gaze behavior in prepubertal Vietnamese children living in Da Nang, a hot spot for dioxin contamination

Previous studies have reported that dioxin exposure alters sexual dimorphism of play behavior in pre-pubertal children. We aimed to investigate the effects of perinatal dioxin exposure, indicated by dioxins in breast milk, on sexual dimorphism of gaze behavior after adjusting for salivary testosterone (T). Participants were pre-pubertal children in a hot spot for dioxin contamination originating from herbicide spraying in Vietnam.We used eye tracking to assess gaze behavior in 172 children (100 boys and 72 girls) aged 8–9 years. Two sets of 15 pairs of pictures, one oriented towards boys and one oriented towards girls, containing 5 pairs of toy photos (non-biological stimuli) and 10 pairs of human line drawings (biological stimuli) were shown to all children. The total fixation duration for each picture was extracted using Tobii studio software and a feminine index of gaze behavior was defined as the ratio of the summed fixation duration for the girl- vs boy-oriented versions of each stimuli.When viewing non-biological stimuli, feminine index scores significantly increased with TCDD (β = 0.294) in girls only. For biological stimuli, however, feminine index scores significantly increased with TEQ-PCDD/Fs (β = 0.269) in boys and with TCDD in girls (β = 0.286). These associations were significant even after adjusting for salivary T levels, which were inversely associated with some dioxin congeners in girls. In addition, increased feminine index scores for biological stimuli were associated with lower cognitive scores for hand-movement and word-order tests in boys and for face-recognition tests in girls examined at 5 years of age.In conclusion, these results suggest that perinatal dioxin exposure may increase visual interest in girl-oriented objects through impairment of cognitive abilities in pre-pubertal Vietnamese children. PCDD congeners were associated with gaze behavior independently of T levels in boys, while this was only the case for TCDD levels in girls.

DNA hydrogel-based gene editing and drug delivery systems.

Deoxyribonucleic acid (DNA) is a promising synthesizer for precisely constructing almost arbitrary geometry in two and three dimensions. Among various DNA-based soft materials, DNA hydrogels are comprised of hydrophilic polymeric networks of crosslinked DNA chains. For their properties of biocompatibility, porosity, sequence programmability and tunable multifunctionality, DNA hydrogels have been widely studied in bioanalysis and biomedicine. In this review, recent developments in DNA hydrogels and their applications in drug delivery systems are highlighted. First, physical and chemical crosslinking methods for constructing DNA hydrogels are introduced. Subsequently, responses of DNA hydrogels to nonbiological and biological stimuli are described. Finally, DNA hydrogel-based delivery platforms for different types of drugs are detailed. With the emergence of gene therapy, this review also gives future prospects for combining DNA hydrogels with the gene editing toolbox.

Suppression of Vascular Macrophage Activation by Nitro-Oleic Acid and its Implication for Abdominal Aortic Aneurysm Therapy.

Abdominal aortic aneurysm (AAA) is one of the leading causes of death in the developed world and is currently undertreated due to the complicated nature of the disease. Herein, we aimed to address the therapeutic potential of a novel class of pleiotropic mediators, specifically a new drug candidate, nitro-oleic acid (NO2-OA), on AAA, in a well-characterized murine AAA model. We generated AAA using a mouse model combining AAV.PCSK9-D377Y induced hypercholesterolemia with angiotensin II given by chronic infusion. Vehicle control (PEG-400), oleic acid (OA), or NO2-OA were subcutaneously delivered to mice using an osmotic minipump. We characterized the effects of NO2-OA on pathophysiological responses and dissected the underlying molecular mechanisms through various in vitro and ex vivo strategies. Subcutaneous administration of NO2-OA significantly decreased the AAA incidence (8/28 mice) and supra-renal aorta diameters compared to mice infused with either PEG-400 (13/19, p =0.0117) or OA (16/23, p = 0.0078). In parallel, the infusion of NO2-OA in the AAA model drastically decreased extracellular matrix degradation, inflammatory cytokine levels, and leucocyte/macrophage infiltration in the vasculature. Administration of NO2-OA reduced inflammation, cytokine secretion, and cell migration triggered by various biological stimuli in primary and macrophage cell lines partially through activation of the peroxisome proliferator-activated receptor-gamma (PPARγ). Moreover, the protective effect of NO2-OA relies on the inhibition of macrophage prostaglandin E2 (PGE2)-induced PGE2 receptor 4 (EP4) cAMP signaling, known to participate in the development of AAA. Administration of NO2-OA protects against AAA formation and multifactorial macrophage activation. With NO2-OA currently undergoing FDA approved phase II clinical trials, these findings may expedite the use of this nitro-fatty acid for AAA therapy.

Poly(vinyl alcohol) and Functionalized Ionic Liquid-Based Smart Hydrogels for Doxorubicin Release.

Limitations associated with the traditional cancer therapies prompt the scientific community to develop effective, safer, smarter, and targeted drug carriers that improve the efficiency of the drug carrier, reduce the adverse effects of the drug on the healthy cells, and help in preventing the cancer recurrences. This research aims to design a stimuli-responsive, self-healable, adhesive, and injectable polymeric hydrogel with an ester-functionalized ionic liquid as one of the additives to improve the efficiency of the anticancer drug in encapsulation and localized delivery. The designed polymeric hydrogel responds to intracellular biological stimuli (e.g., acidic pH of cancerous cells and temperature), changes the morphology through changing the shape and size of the gelator within the hydrogel matrix, and releases encapsulated doxorubicin (DOX) at the tumor site efficiently. Molecular interactions, gel morphology, and mechanical strength of the hydrogel were characterized through various analytical techniques, including small-angle neutron scattering. Adhesive properties of the polymeric hydrogel were measured by lap-shear strength tests and the biocompatibility and cellular drug uptake study on human breast cancer (MCF-7) and human cervical carcinoma cells (HeLa). The in vitro cytotoxicity and drug release study showed that the hybrid hydrogel is more effective at killing the cancerous cells, and the targeted release of DOX occurred at intracellular acidic pH. The polymeric hydrogel provides an efficient therapeutic approach for the encapsulation and release of the drug. Overall, the study offers a proof of concept to test the feasibility of the hydrogel system whether the hydrogel formulation helped or hindered the total cellular DOX trafficking.

Imaging spectrum of periosteal lesions – Pictorial essay

Periosteum is a multipotential membrane giving rise to variety of reactions when mineralized. Any stimulus mechanical, physiological, biological and pathological stimulus can produce periosteal reaction and is best seen on conventional films. However, in order to detect early periosteal reaction, Ultrasonography is the mode of choice of investigation. There is a spectrum of imaging findings but no one really is specific. The number of etiological factors as well as the number of imaging features are listed and described. The message is that periosteal reaction is a radiological sign and not a disease, although is encountered in many focal, multifocal and systemic disorders.

Hub Proteins Involved in RAW 264.7 Macrophages Exposed to Direct Current Electric Field.

At present, studies on macrophage proteins mainly focus on biological stimuli, with less attention paid to the responses of macrophage proteins to physical stimuli, such as electric fields. Here, we exploited the electric field-sensitive hub proteins of macrophages. RAW 264.7 macrophages were treated with a direct current electric field (dcEF) (200 mV/mm) for four hours, followed by RNA-Seq analysis. Differentially expressed genes (DEGs) were obtained, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and protein–protein interaction (PPI) analysis. Eight qPCR-verified DEGs were selected. Subsequently, three-dimensional protein models of DEGs were modeled by Modeller and Rosetta, followed by molecular dynamics simulation for 200 ns with GROMACS. Finally, dcEFs (10, 50, and 500 mV/mm) were used to simulate the molecular dynamics of DEG proteins for 200 ns, followed by trajectory analysis. The dcEF has no obvious effect on RAW 264.7 morphology. A total of 689 DEGs were obtained, and enrichment analysis showed that the steroid biosynthesis pathway was most affected by the dcEF. Moreover, the three-dimensional protein structures of hub proteins were constructed, and trajectory analysis suggested that the dcEF caused an increase in the atomic motion of the protein in a dcEF-intensity-dependent manner. Overall, we provide new clues and a basis for investigating the hub proteins of macrophages in response to electric field stimulation.

Photobiomodulation-Induced Differentiation of Immortalized Adipose Stem Cells to Neuronal Cells.

Transdermal differentiation of human adipose stem cells (ASCs) to other cell types is still a challenge in regenerative medicine. Studies using primary ASCs are also limited as they may undergo replicative senescence during repeated passages in vitro. However, ASCs immortalized (iASCs) with human telomerase enzyme expressing plasmid exhibits a uniform population suitable for differentiation in vitro. A right combination of biological and physical stimuli may induce transdermal differentiation of iASCs into neurons in vitro. iASCs were differentiated to free-floating neural stem cell aggregates (neurospheres) using a combination of growth inducers. Cells in these spheres were induced to differentiate into neurons using low-intensity lasers by a process called photobiomodulation (PBM). Laser at the near infrared (NIR) wavelength 825 nm and fluences 5, 10, and 15 J/cm2 was capable of increasing the differentiation of neurospheres to neurons. Precisely, there was a statistically significant increase in the early neuronal marker at 5 J/cm2 and a much appreciable increase at 15 J/cm2 in correlation with the biphasic dose response of PBM. However, these differentiated cells failed to express late neuronal markers in vitro. Comparison of these differentiating iASCs with the primary ASCs revealed a sharp distinction between the metabolic processes of the primary ASCs, neurospheres, and newly differentiated neurons. We found that PBM increased the yield of neurons and effected stem cell differentiation through modulation of cellular metabolism and redox status. Our study also identifies that iASCs are an excellent model for analysis of stem cell biology and for performing transdermal differentiation. This study demonstrates that a combination of biological and physical inducers can advance the differentiation of adipose stem cells to neurons. We were able to establish the optimal energy for the neuronal differentiation of iASCs in vitro. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Novel markers for high-throughput protoplast-based analyses of phytohormone signaling.

Phytohormones mediate most diverse processes in plants, ranging from organ development to immune responses. Receptor protein complexes perceive changes in intracellular phytohormone levels and trigger a signaling cascade to effectuate downstream responses. The in planta analysis of elements involved in phytohormone signaling can be achieved through transient expression in mesophyll protoplasts, which are a fast and versatile alternative to generating plant lines that stably express a transgene. While promoter-reporter constructs have been used successfully to identify internal or external factors that change phytohormone signaling, the range of available marker constructs does not meet the potential of the protoplast technique for large scale approaches. The aim of our study was to provide novel markers for phytohormone signaling in the Arabidopsis mesophyll protoplast system. We validated 18 promoter::luciferase constructs towards their phytohormone responsiveness and specificity and suggest an experimental setup for high-throughput analyses. We recommend novel markers for the analysis of auxin, abscisic acid, cytokinin, salicylic acid and jasmonic acid responses that will facilitate future screens for biological elements and environmental stimuli affecting phytohormone signaling.

PERCEIVED AESTHETIC FEATURES DIFFERENTIATING BETWEEN COMPLEX ARTISTIC DANCE SKILLS OF VARYING STYLE

Research on (empirical) aesthetics investigates properties and features of objects, the resulting response-mechanisms to such objects in the observer, and the interplay between factors of the object and the observer in a given context. This study focuses on object-related factors, such as biological motion. The question is addressed of whether there are perceived aesthetic features differentiating between complex artistic skills ranked most and least aesthetic by experienced observers. Therefore, 18 participants with dance experience were asked to evaluate the perceived aesthetics of stick-figure video sequences of three different complex motor skills, namely dance jumps, poses, and turns. As a result, three specific aesthetic features are pointed out as aesthetic fundamentals in the perception and evaluation of aesthetic sports and performing arts: 1) an outwards direction away from the dancers longitudinal axis and body center, 2) a focus on external rotation of the limbs (turn-out), and 3) a (diagonal) spread of body movements creating the impression of elongating the dancer’s body. In particular, aesthetic features that demand the performer’s ability and challenge physical laws seem to be robust parameters when aiming to create aesthetic motion stimuli. Concluding, a skill-specificity for aesthetic features, as well as the need to differentiate between the interaction of different aesthetic features, is pointed out – aspects which seem especially apparent in biological motion stimuli.

Reduced Plasma Lipid Mediators Are Directly Associated with Low Vitamin A Status in Women from Western Samar, Philippines

Abstract Objectives Vitamin A (VA) is an essential micronutrient that plays a key role in many biological processes, including growth, vision, immunity and reproduction. While evidence has been established to support these mechanisms, new studies suggest there may be more signaling compounds that are impacted by VA status. Lipid mediators, such as oxylipins and lysophospholipids, are signaling compounds that, in response to biological stimuli, exhibit regulatory effects on inflammation, immune function, vascular tone, and other systems. The objective was to investigate differences in lipid mediators associated with VA status. Methods In this cross-sectional study, blood samples from women in Western Samar, Philippines, were selected based on plasma retinol concentration indicating adequate (n = 5) or low (n = 5) VA status (retinol &amp;lt; 0.7 μmol/L). Retinol was measured using an Agilent 1200 HPLC-DAD. Oxylipin, endocannabinoid, bile acid, and lipidomics assays were analyzed on a Waters Acquity UPLC and detected using multiple reaction monitoring on a Sciex 4000 QTRAP. Data were adjusted for covariates related to the acute phase response, age, and BMI. Results Twenty-four lipid mediators were lower in the low VA status group (P &amp;lt; 0.05). These lipid mediators included the arachidonic acid-derived oxylipins’ lipoxin A4 and 6-trans-LTB4 formed via lipoxygenases (LOX), as well as the cyclooxygenase (COX) product PGD2. Several LOX and soluble epoxide hydrolase (sEH) oxylipins produced from eicosapentaenoic acid and the acylethanolamides LEA and PEA were lower (P &amp;lt; 0.05) in individuals with low plasma retinol levels. Numerous phospholipids and sphingolipids were also lower (P &amp;lt; 0.05) with decreased VA status, including two lysophosphatidylcholines, three lysophosphatidylethanolamines, two phosphatidylcholines, and two sphingomyelins. Conclusions In this exploratory study, VA status was directly associated with lipid mediator concentrations. Future studies testing the biological impact of lipid mediator changes with varying levels of VA status are necessary. Funding Sources NIH U24 DK097154, USDA Intramural Project 2032–51,530-022–00D, NIH T32-GM008799, Cal Poly CAFES SURP.

Innovation in Skin Regeneration: Novel Approaches with β-1,3/1,6-Glucan-Based Treatments

Skin regeneration is a multidisciplinary topic that involves plastic surgery, aesthetics, and dermatology. In the last few years, several molecules have been used to prevent or delay the skin aging process. Recently, promising investigations on novel β-1,3/1,6-glucan-based treatments, associated with sodium hyaluronate, have demonstrated the induction of a naive biological stimulus in soft tissues. Serum Revitalizing Face (Lot 00118a0051 of 11/19/2018 approved by the Italian Ministry of Health as a Medical Device-Class I) was administered mainly on the face and forearms of the enrolled patients. The Serum Revitalizing Face was administered at T0 (first week), T1 (second week), and T2 (third week). Patients were asked to apply 1.5 mL of the serum on their skin until the product was completely absorbed. All patients were also examined by clinical assessments at different time points. The results showed that a daily application of the β-1,3/1,6-glucan induced a statistically significant increase in the elasticity of the skin.

MechanoBioTester: A Decoupled Multistimulus Cell Culture Device for Studying Complex Microenvironments In Vitro.

Increasingly being recognized is the role of the complex microenvironment to regulate cell phenotype; however, the cell culture systems used to study these effects in vitro are lagging. The complex microenvironment is host to a combination of biological interactions, chemical factors, and mechanical stimuli. Many devices have been designed to probe the effects of one mechanical stimulus, but few are capable of systematically interrogating all combinations of mechanical stimuli with independent control. To address this gap, we have developed the MechanoBioTester platform, a decoupled, multi-stimulus cell culture model for studying the cellular response to complex microenvironments in vitro. The system uses an engineered elastomeric chamber with a specially defined region for incorporating different target materials to act as the cell culture substrate. We have tested the system with several target materials including: polydimethylsiloxane elastomer, polyacrylamide gel, poly(1,8-octanediol citrate) elastomer, and type I collagen gel for both 2D and 3D co-culture. Additionally, when the chamber is connected to a flow circuit and our stretching device, stimuli in the form of fluid flow, cyclic stretch, and hydrostatic pressure are able to be imparted with independent control. We validated the device using experimental and computational methods to define a range of capabilities relevant to physiological microenvironments. The MechanoBioTester platform promises to function as a model system for mechanobiology, biomaterial design, and drug discovery applications that focus on probing the impact of a complex microenvironment in an in vitro setting. The protocol described within provides the details characterizing the MechanoBioTester system, the steps for fabricating the MechanoBioTester chamber, and the procedure for operating the MechanoBioTester system to stimulate cells.

Optical Control of Cytokine Signaling via Bioinspired, Polymer-Induced Latency.

Cytokine signaling is challenging to study and therapeutically exploit as the effects of these proteins are often pleiotropic. A subset of cytokines can, however, achieve signal specificity via association with latency-inducing proteins, which cage the cytokine until disrupted by discreet biological stimuli. Inspired by this precision, here, we describe a strategy for synthetic induction of cytokine latency via modification with photolabile polymers that mimic latency while attached then restore protein activity in response to light, thus controlling the magnitude, duration, and location of cytokine signals. We characterize the high dynamic range of cytokine activity modulation and find that polymer-induced latency, alone, can prolong in vivo circulation and bias receptor subunit binding. We further show that protein derepression can be achieved with a near single-cell resolution and demonstrate the feasibility of transcutaneous photoactivation. Future extensions of this approach could enable multicolor, optical reprogramming of cytokine signaling networks and more precise immunotherapies.