Inflammatory environment-adaptive patterned surface for spatiotemporal immunomodulation of macrophages.

Designing biomaterials with precise immunomodulation can help to decipher the dynamic interactions between macrophages and biomaterials to match the tissue healing process. Although some advanced stimuli-responsive immunomodulatory biomaterials were reported for cell dynamic modulation, while most triggers need external stimuli by manual intervention, there would be the inevitable errors and uncertainties. Thus, developing immunomodulatory biomaterials with adaptive abilities, which can recognize the inflammation signals, change their properties spatiotemporally under the microenvironment triggers, and provide feedback to realize macrophages modulation in different healing stages, has become a promising strategy. In this work, we developed an inflammation-adaptive Arg-Gly-Asp (RGD) -patterned surface for spatiotemporal immunomodulation of macrophage. We fabricated a methacrylated hyaluronic acid (MA-HA) hydrogel with thiol-functionalized RGD-patterned surface by employing photolithography technology. Then, thiol-functionalized RGD contained ROS-cleavable linker was filled the remaining sites and consequently, a dynamic surface with temporary homogeneous RGD was obtained. Under the overproduction of ROS by the inflammation-activated macrophages, the linker was cleaved, and the homogeneous RGD surface was transformed to the RGD patterned surface, which triggered elongation of macrophages and consequently the upregulated expressions of arginase-1, IL-10 and TNF-ß1, indicating the polarization toward to anti-inflammatory phenotype. Developing inflammatory environment-adaptive surface for spatiotemporal modulation of macrophages polarization provides a precise and smart strategy for the healing-matched immunomodulation to facilitate healing outcomes. STATEMENT OF SIGNIFICANCE: Designing biomaterials with precise immunomodulation can help to decipher the dynamic interactions between macrophages and biomaterials to match tissue repair process. Some immunomodulatory biomaterials were reported for cell dynamic modulation, while most triggers need external manual intervention. Thus, we developed an immunomodulatory biomaterial with inflammation-adaptive patterned surface, which can recognize abnormal signals and change its properties spatiotemporally under the microenvironment triggers, and provide feedback to realize macrophages modulation in different stages. The dynamic surface can adapt to the changes of microenvironment and dynamically to match the cell behavior and tissue healing process on demand without external manual intervention. Additionally, the surface achieves the balance of macrophages with pro- and anti-inflammatory phenotypes in the tissue repair process.

The effects of thermal treatment on emulsifying properties of soy protein isolates: Interfacial rheology and quantitative proteomic analysis.

In this work, the interfacial rheological properties and the quantitative changes of proteins at interfacial protein layers of emulsions stabilized by soy protein isolates (SPI) and heat-treated soy protein isolates (HSPI) were investigated. The quantification results showed that the relative quantities of albumin (2S) and glycinin (11S) in SPI decreased at the oil-water interface, suggesting that they possessed lower interfacial affinities at the interface. Basic 7S globulin presented more adsorption at the oil-water interface due to the well balance of the hydrophobic and hydrophilic groups of its amino acid sequence. The HSPI (95 °C, 20 min) showed a larger apparent diffusion rate (Kdiff) and a shorter equilibrium adsorption time. The results of interfacial rheology of globulins were consistent with their interfacial quantitative changes, which demonstrated that the interfacial behavior and adsorption ability of globulin were improved by thermal treatment. In this research, the interfacial behaviors of SPI and HSPI was illustrated by their interfacial properties and quantitative results of interfacial adsorbed protein layers, would promote a profound comprehension for the interfacial behavior of the protein and the influence of thermal treatment on protein interfacial properties.

An Acellular Scaffold Facilitates Endometrial Regeneration and Fertility Restoration via Recruiting Endogenous Mesenchymal Stem Cells.

Severe intrauterine adhesions (IUAs), characterized by inadequate endometrial repair and fibrosis, can lead to infertility. Stem cell-based therapies, which deliver mesenchymal stem cells (MSCs) to the wound site, hold a considerable promise for endometrium regeneration. However, some notable hurdles, such as stemness loss, immunogenicity, low retention and survival rate, limit their clinical application. Evidence shows a strategy of mobilizing endogenous MSCs recruitment can overcome the traditional limitations of exogenous stem cell-based therapies. Here, an acellular biomaterial named stromal derived factor-1 alpha (SDF-1α)/E7-modified collagen scaffold (CES) is explored. CES based on harnessing the innate regenerative potential of the body enables near-complete endometrium regeneration and fertility restoration both in a rat endometrium acute damage model and a rat IUA model. Mechanistically, the CES implantation promotes endogenous MSCs recruitment via a macrophage-coordinated strategy; then the homing MSCs exert the function of immunomodulation and altered local microenvironments toward regeneration. To conclude, CES, which can harness endogenous MSCs and overcome the traditional limitations of cell-based therapies, can serve as a clinically feasible and cell-free strategy with high therapeutic efficiency for IUA treatment.

A "sandwich" cell culture platform with NIR-responsive dynamic stiffness to modulate macrophage phenotypes.

Considering the key roles of macrophages in tissue repair and immune therapy, designing smart biomaterials able to harness macrophage phenotypes on demand during the healing process has become a promising strategy. Here, a novel "sandwich" cell culture platform with near-infrared (NIR) responsive dynamic stiffness was fabricated to polarize bone marrow-derived macrophages (BMDMs) in situ for revealing the relationship between the macrophage phenotype and substrate stiffness dynamically. Under NIR irradiation, calcium ions (Ca2+) diffused through the middle layer of the IR780-mixed phase change material (PCM) due to the photothermal effect of IR780, resulting in an increase of hydrogel stiffness in situ by the crosslinking of the upper layer of the hyaluronic acid-sodium alginate hydrogel (MA-HA&SA). The up-regulation of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) was quantified by immunostaining and enzyme-linked immune sorbent assay (ELISA), respectively, indicating the transformation of macrophages from the anti-inflammatory to pro-inflammatory phenotype under dynamic stiffness. The nuclear Yes-associated-protein (YAP) ratio positively correlated with the shift of the macrophage phenotype. The modulation of macrophage phenotypes by stiffness-rise without the stimuli of cytokines offers an effective and noninvasive strategy to manipulate immune reactions to achieve optimized healing or therapeutic outcomes.

Light-induced dynamic RGD pattern for sequential modulation of macrophage phenotypes.

Due to the critical roles of macrophage in immune response and tissue repair, harnessing macrophage phenotypes dynamically to match the tissue healing process on demand attracted many attentions. Although there have developed many advanced platforms with dynamic features for cell manipulation, few studies have designed a dynamic chemical pattern to sequentially polarize macrophage phenotypes and meet the immune requirements at various tissue repair stages. Here, we propose a novel strategy for spatiotemporal manipulation of macrophage phenotypes by a UV-induced dynamic Arg-Gly-Asp (RGD) pattern. By employing a photo-patterning technique and the specific interaction between cyclodextrin (CD) and azobenzene-RGD (Azo-RGD), we prepared a polyethylene glycol-dithiol/polyethylene glycol-norbornene (PEG-SH/PEG-Nor) hydrogel with dynamic RGD-patterned surface. After irradiation with 365-nm UV light, the homogeneous RGD surface was transformed to the RGD-patterned surface which induced morphological transformation of macrophages from round to elongated and subsequent phenotypic transition from pro-inflammation to anti-inflammation. The mechanism of phenotypic polarization induced by RGD pattern was proved to be related to Rho-associated protein kinase 2 (ROCK2). Sequential modulation of macrophage phenotypes by the dynamic RGD-patterned surface provides a remote and non-invasive strategy to manipulate immune reactions and achieve optimized healing outcomes.

Smart wound dressing for infection monitoring and NIR-triggered antibacterial treatment.

Wound infection is a major challenge in the clinic that greatly hinders the wound healing process. It is highly important to develop smart wound dressings that can sense bacterial infection at early stages and provide on-demand treatment. In this work, a smart hydrogel-based wound dressing capable of monitoring bacterial infection via a pH-responsive fluorescence resonance energy transfer (FRET) transition of Cyanine3 (Cy3) and Cyanine5 (Cy5) in a bacterial environment and providing on-demand treatment of infection via near infrared (NIR) light-triggered antibiotic release was developed. The smart hydrogel was prepared by physical crosslinking of polyvinyl alcohol (PVA) and an ultraviolet (UV)-cleavable polyprodrug (GS-Linker-MPEG), in which Cy3 and Cy5-modified silica nanoparticles (SNP-Cy3/Cy5) were loaded and acted as a pH-responsive fluorescent probe to detect bacterial infection based on the FRET effect between Cy3 and Cy5. Also, up-conversion nanoparticles (UCNP) were loaded into the hydrogels to cleave the UV-responsive GS-Linker-MPEG and achieve NIR-responsive release of GS in the bacterial environment. The in vitro studies proved that the smart hydrogels present good water absorption ability and excellent mechanical properties as well as good biocompatibility, which are necessary for their application in wound dressings. Moreover, the hydrogels showed obvious FRET transitions in both acidic buffer and bacteria solution. Upon irradiating the hydrogels with NIR light, UCNP were able to convert NIR light to UV light to trigger the release of GS from the hydrogels for antibacterial treatment. This research is expected to provide a new strategy for self-reporting and effective treatment of wound infection.

Near-Infrared-Triggered Dynamic Surface Topography for Sequential Modulation of Macrophage Phenotypes.

Immune response is critical to tissue repair. Designing biomaterials with immunomodulatory functions has become a promising strategy to facilitate tissue repair. Considering the key roles of macrophages in tissue repair and the significance of the balance of M1 and M2, smart biomaterials, which can harness macrophage phenotypes dynamically to match the tissue healing process on demand, have attracted a lot of attention to be set apart from the traditional anti-inflammatory biomaterials. Here, we prepare a gold nanorod-contained shape memory polycaprolactone film with dynamic surface topography, which has the ability to be transformed from flat to microgrooved under near-infrared (NIR) irradiation. Based on the close relationships between the morphologies and the phenotypes of macrophages, the NIR-triggered surface transformation induces the elongation of macrophages, and consequently the upregulated expressions of arginase-1 and IL-10 in vitro, indicating the change of macrophage phenotypes. The sequential modulation of macrophage phenotypes by dynamic surface topography is further confirmed in an in vivo implantation test. The healing-matched modulation of macrophage phenotypes by dynamic surface topography without the stimuli of cytokines offers an effective and noninvasive strategy to manipulate tissue regenerative immune reactions to achieve optimized healing outcomes.

Portable nuclear magnetic resonance biosensor and assay for a highly sensitive and rapid detection of foodborne bacteria in complex matrices.

BACKGROUND: Nuclear magnetic resonance (NMR) technique is a powerful analytical tool in determining the presence of bacterial contaminants in complex biological samples. In this paper, a portable NMR-based (pNMR) biosensor and assay to detect the foodborne bacteria Escherichia coli O157:H7 is reported. It uses antibody-functionalized polymer-coated magnetic nanoparticles as proximity biomarker of the bacteria which accelerates NMR resonance signal decay. RESULTS: The pNMR biosensor operates at 0.47 Tesla of magnetic strength and consists of a high-power pulsed RF transmitter and an ultra-low noise sensing circuitry capable of detecting weak NMR signal at 0.1 µV. The pNMR biosensor assay and sensing mechanism is used in detecting E. coli O157:H7 bacteria in drinking water and milk samples. Experimental results demonstrate that by adding a filtration step in the assay, the pNMR biosensor is able to detect E. coli O157:H7 as low as 76 CFU/mL in water samples and as low as 92 CFU/mL in milk samples in about one min. CONCLUSION: The pNMR biosensor assay and sensing system is innovative for foodborne bacterial detection in food matrices. The lowest detection level for E. coli O157:H7 in water and milk samples is essentially 101 CFU/mL. Although the linear range of detection is only from 101 to 104 CFU/mL, the wider detection range spans from 101 CFU/mL to 107 CFU/mL. Existing pNMR biosensors have detection limits at 103-104 CFU/mL only. The detection technique can be extended to other microbial or viral organisms by merely changing the specificity of the antibodies. Besides food safety, the pNMR biosensor described in this paper has potential to be applied as a rapid detection device in biodefense and healthcare diagnostic applications.

Surface functionalization of electrospun nanofibers for detecting E. coli O157:H7 and BVDV cells in a direct-charge transfer biosensor.

Electrospinning is a versatile and cost effective method to fabricate biocompatible nanofibrous materials. The novel nanostructure significantly increases the surface area and mass transfer rate, which improves the biochemical binding effect and sensor signal to noise ratio. This paper presents the electrospinning method of nitrocellulose nanofibrous membrane and its antibody functionalization for application of bacterial and viral pathogen detection. The capillary action of the nanofibrous membrane is further enhanced using oxygen plasma treatment. An electrospun biosensor is designed based on capillary separation and conductometric immunoassay. The silver electrode is fabricated using spray deposition method which is non-invasive for the electrospun nanofibers. The surface functionalization and sensor assembly process retain the unique fiber morphology. The antibody attachment and pathogen binding effect is verified using the confocal laser scanning microscope (CLSM) and scanning electronic microscope (SEM). The electrospun biosensor exhibits linear response to both microbial samples, Escherichia coli O157:H7 and bovine viral diarrhea virus (BVDV) sample. The detection time of the biosensor is 8 min, and the detection limit is 61 CFU/mL and 10(3)CCID/mL for bacterial and viral samples, respectively. With the advantage of efficient antibody functionalization, excellent capillary capability, and relatively low cost, the electrospinning process and surface functionalization method can be implemented to produce nanofibrous capture membrane for different immuno-detection applications.