Radiomics-based prediction of response to immune checkpoint inhibitor treatment for solid cancers using computed tomography: a real-world study of two centers.

BACKGROUND: Immune checkpoint inhibitors (ICIs) represent an approved treatment for various cancers; however, only a small proportion of the population is responsive to such treatment. We aimed to develop and validate a plain CT-based tool for predicting the response to ICI treatment among cancer patients. METHODS: Data for patients with solid cancers treated with ICIs at two centers from October 2019 to October 2021 were randomly divided into training and validation sets. Radiomic features were extracted from pretreatment CT images of the tumor of interest. After feature selection, a radiomics signature was constructed based on the least absolute shrinkage and selection operator regression model, and the signature and clinical factors were incorporated into a radiomics nomogram. Model performance was evaluated using the training and validation sets. The Kaplan-Meier method was used to visualize associations with survival. RESULTS: Data for 122 and 30 patients were included in the training and validation sets, respectively. Both the radiomics signature (radscore) and nomogram exhibited good discrimination of response status, with areas under the curve (AUC) of 0.790 and 0.814 for the training set and 0.831 and 0.847 for the validation set, respectively. The calibration evaluation indicated goodness-of-fit for both models, while the decision curves indicated that clinical application was favorable. Both models were associated with the overall survival of patients in the validation set. CONCLUSIONS: We developed a radiomics model for early prediction of the response to ICI treatment. This model may aid in identifying the patients most likely to benefit from immunotherapy.

Rice WRKY4 acts as a transcriptional activator mediating defense responses toward Rhizoctonia solani, the causing agent of rice sheath blight.

WRKY transcription factors have been implicated in the regulation of transcriptional reprogramming associated with various plant processes but most notably with plant defense responses to pathogens. Here we demonstrate that expression of rice WRKY4 gene (OsWRKY4) was rapidly and strongly induced upon infection of Rhizoctonia solani, the causing agent of rice sheath blight, and exogenous jasmonic acid (JA) and ethylene (ET). OsWRKY4 is localized to the nucleus of plant cells and possesses transcriptional activation ability. Modulation of OsWRKY4 transcript levels by constitutive overexpression increases resistance to the necrotrophic sheath blight fungus, concomitant with elevated expression of JA- and ET-responsive pathogenesis-related (PR) genes such as PR1a, PR1b, PR5 and PR10/PBZ1. Suppression by RNA interference (RNAi), on the other hand, compromises resistance to the fungal pathogen. Yeast one-hybrid assay and transient expression in tobacco cells reveal that OsWRKY4 specifically binds to the promoter regions of PR1b and PR5 which contain W-box (TTGAC[C/T]), or W-box like (TGAC[C/T]) cis-elements. In conclusion, we propose that OsWRKY4 functions as an important positive regulator that is implicated in the defense responses to rice sheath blight via JA/ET-dependent signal pathway.

A bioinspired injectable antioxidant hydrogel for prevention of postoperative adhesion.

Postoperative adhesions, a prevalent complication following abdominal surgery, affect 90% of patients undergoing abdominal surgical procedures. Currently, the primary approach to prevent postoperative adhesions involves physical isolation of the surgical site and surrounding tissues using a hydrogel; however, this method represents a rudimentary strategy. Herein, considering the impact of oxidative stress and free radicals on postoperative adhesion during wound healing, an injectable antioxidant hydrogel, named PU-OHA-D, was successfully synthesized, which is formed by the crosslinking of dopamine-modified oxidized hyaluronic acid (OHA-D) and dihydrazide-terminated polyurethane (PU-ADH) through hydrazone bonding. PU-OHA-D hydrogel possesses versatile characteristics such as rapid gel formation, injectability, self-repair capability and biodegradability. Additionally, they exhibit an excellent ability to clear free radicals and superior tissue adhesion. PU-OHA-D can be injected in situ to form a hydrogel to prevent abdominal wall-cecum adhesion. Importantly, it can effectively eliminate free radicals and inhibit oxidative stress at the wound site. Thereby, it leads to collagen physiological degradation and prevents the occurrence of postoperative adhesions. The bioinspired hydrogel demonstrates its great potential in preventing postoperative adhesion and promoting wound healing.

AMPK-a key factor in crosstalk between tumor cell energy metabolism and immune microenvironment?

Immunotherapy has now garnered significant attention as an essential component in cancer therapy during this new era. However, due to immune tolerance, immunosuppressive environment, tumor heterogeneity, immune escape, and other factors, the efficacy of tumor immunotherapy has been limited with its application to very small population size. Energy metabolism not only affects tumor progression but also plays a crucial role in immune escape. Tumor cells are more metabolically active and need more energy and nutrients to maintain their growth, which causes the surrounding immune cells to lack glucose, oxygen, and other nutrients, with the result of decreased immune cell activity and increased immunosuppressive cells. On the other hand, immune cells need to utilize multiple metabolic pathways, for instance, cellular respiration, and oxidative phosphorylation pathways to maintain their activity and normal function. Studies have shown that there is a significant difference in the energy expenditure of immune cells in the resting and activated states. Notably, competitive uptake of glucose is the main cause of impaired T cell function. Conversely, glutamine competition often affects the activation of most immune cells and the transformation of CD4+T cells into inflammatory subtypes. Excessive metabolite lactate often impairs the function of NK cells. Furthermore, the metabolite PGE2 also often inhibits the immune response by inhibiting Th1 differentiation, B cell function, and T cell activation. Additionally, the transformation of tumor-suppressive M1 macrophages into cancer-promoting M2 macrophages is influenced by energy metabolism. Therefore, energy metabolism is a vital factor and component involved in the reconstruction of the tumor immune microenvironment. Noteworthy and vital is that not only does the metabolic program of tumor cells affect the antigen presentation and recognition of immune cells, but also the metabolic program of immune cells affects their own functions, ultimately leading to changes in tumor immune function. Metabolic intervention can not only improve the response of immune cells to tumors, but also increase the immunogenicity of tumors, thereby expanding the population who benefit from immunotherapy. Consequently, identifying metabolic crosstalk molecules that link tumor energy metabolism and immune microenvironment would be a promising anti-tumor immune strategy. AMPK (AMP-activated protein kinase) is a ubiquitous serine/threonine kinase in eukaryotes, serving as the central regulator of metabolic pathways. The sequential activation of AMPK and its associated signaling cascades profoundly impacts the dynamic alterations in tumor cell bioenergetics. By modulating energy metabolism and inflammatory responses, AMPK exerts significant influence on tumor cell development, while also playing a pivotal role in tumor immunotherapy by regulating immune cell activity and function. Furthermore, AMPK-mediated inflammatory response facilitates the recruitment of immune cells to the tumor microenvironment (TIME), thereby impeding tumorigenesis, progression, and metastasis. AMPK, as the link between cell energy homeostasis, tumor bioenergetics, and anti-tumor immunity, will have a significant impact on the treatment and management of oncology patients. That being summarized, the main objective of this review is to pinpoint the efficacy of tumor immunotherapy by regulating the energy metabolism of the tumor immune microenvironment and to provide guidance for the development of new immunotherapy strategies.

Molecular mechanism underlying epithelial-mesenchymal transformation and cisplatin resistance in esophageal squamous cell carcinoma.

Esophageal cancer (EC) occupies the seventh spot of the most prevalent malignancy cancer ailments worldwide and the sixth leading cause of cancer-related death. Esophageal squamous cell carcinoma (ESCC) is also the most predominant histological subtype of EC, and cisplatin (DDP) is commonly used as a first-line chemotherapeutic drug for the late advanced stages of the disease. However, the emergence of drug resistance during clinical treatment possesses a significant challenge to the therapeutic success and patient outcomes. Collectively, the epithelial-mesenchymal transformation (EMT) is a process in which transcription factors are induced to regulate the expression of epithelial and stromal markers to promote the differentiation of epithelial cells into stromal cells. Recent studies have demonstrated a close association between EMT and chemotherapy resistance in tumor cells, with concrete evidence of reciprocal reinforcement. Therefore, in this review, we elucidate the molecular mechanism underlying ESCC, shed light on the mechanisms driving DDP resistance, and provide insights into the intricate interplay between EMT and ESCC. We have aimed to provide some new hypotheses and perspectives that may address-inform future therapeutic strategies for ESCC treatment.

[Visual trephine arthroplasty assisted percutaneous transforaminal endoscopic discectomy for lumbar disc herniation].

OBJECTIVE: To compare the clinical efficacy between visual trephine arthroplasty assisted percutaneous transforaminal endoscopic discectomy (VPTED) and traditional percutaneous transforaminal endoscopic discectomy(PTED) in the treatment of lumbar disc herniation. METHODS: The clinical data of 60 patients with lumbar disc herniation admitted from June 2019 to December, 2020 was retrospectively analyzed. There were 38 males and 22 females, aged from 26 to 58 years old with an average of (43.63±8.48) years, 47 cases were on L4,5 segment and 13 cases were on L5S1 segment. Among them, 32 were treated with VPTED (group A) and 28 were treated with traditional PTED (group B). The general conditions of all the patients were recorded, including intraoperative fluoroscopy times, operation time, hospital stay and surgical complications during follow-up. The arthroplasty area ratio was observed by sagittal CT at the middle level of the intervertebral foramen. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score of low back pain, Oswestry disability index (ODI) were used to evaluate the clinical efficacy between two groups. RESULTS: All patients were followed up from 9 to 15 months with an average of (12.10±1.16) months. There was no statistical difference of preoperative general data between two groups. The operation time, fluoroscopy times and hospital stay were (70.47±5.87) min, (13.66±1.34) times and (6.31±0.69) d in group A, and (90.71±7.66) min, (22.82±2.48) times and (6.54±0.92) d in group B. The operation time and intraoperative fluoroscopy times in group A were lower than those in group B(P<0.05). There was no significant difference in hospital stay between two groups (P>0.05). No obvious surgical complications were found during the follow-up in both groups. The arthroplasty area ratio in group A was (29.72±2.84)% and (29.57±2.20)% in group B, respectively, with no significant difference (P>0.05). There was no significant difference in VAS, ODI and JOA score between two groups before operation and at the final follow-up(P>0.05), but the final follow-up was significantly improved(P<0.05). CONCLUSION: The two surgical methods have definite clinical efficacy in the treatment of lumbar disc herniation. Visual trephine arthroplasty assisted percutaneous transforaminal endoscopic discectomy has the advantages of high efficiency and rapidity when establishing the channel, and can significantly reduce the operation time and intraoperative fluoroscopy times.

Advances in the Application of Preclinical Models in Photodynamic Therapy for Tumor: A Narrative Review.

Photodynamic therapy (PDT) is a non-invasive laser light local treatment that has been utilized in the management of a wide variety of solid tumors. Moreover, the evaluation of efficacy, adverse reactions, the development of new photosensitizers and the latest therapeutic regimens are inseparable from the preliminary exploration in preclinical studies. Therefore, our aim was to better comprehend the characteristics and limitations of these models and to provide a reference for related research. METHODS: We searched the databases, including PubMed, Web of Science and Scopus for the past 25 years of original research articles on the feasibility of PDT in tumor treatment based on preclinical experiments and animal models. We provided insights into inclusion and exclusion criteria and ultimately selected 40 articles for data synthesis. RESULTS: After summarizing and comparing the methods and results of these studies, the experimental model selection map was drawn. There are 7 main preclinical models, which are used for different research objectives according to their characteristics. CONCLUSIONS: Based on this narrative review, preclinical experimental models are crucial to the development and promotion of PDT for tumors. The traditional animal models have some limitations, and the emergence of organoids may be a promising new insight.

Constitutive expression of rice WRKY30 gene increases the endogenous jasmonic acid accumulation, PR gene expression and resistance to fungal pathogens in rice.

WRKY transcription factors are crucial regulatory components of plant responses to pathogen infection. In the present study, we report isolation and functional characterization of the pathogen-responsive rice WRKY30 gene, whose transcripts accumulate rapidly in response to salicylic acid (SA) and jasmonic acid (JA) treatment. Overexpression of WRKY30 in rice enhanced resistance to rice sheath blight fungus Rhizoctonia solani and blast fungus Magnaporthe grisea. The enhanced resistance in the transgenic lines overexpressing WRKY30 was associated with activated expression of JA synthesis-related genes LOX, AOS2 and pathogenesis-related (PR)3 and PR10, and increased endogenous JA accumulation under the challenge of fungal pathogens. WRKY30 was nuclear-localized and had transcriptional activation ability in yeast cells, supporting that it functions as a transcription factor. Together, our findings indicate that JA plays a crucial role in the WRKY30-mediated defense responses to fungal pathogens, and that the rice WRKY30 seems promising as an important candidate gene to improve disease resistance in rice.

Association between eight hypermethylation-related genes and gastric cancer: a systematic review and meta-analysis.

Background: Although multiple gene promoter hypermethylation has been associated with gastric carcinogenesis, data on their specific relationship remains scant. We aimed to investigate the correlation between the status of multiple gene promoter methylation and gastric cancer (GC). Methods: We searched PubMed, EMBASE, CNKI, Wanfang, Cqvip and Cochrane Library up to May 2021. We systematically assessed the association between methylation status of the CpG islands and the risk of GC. We compared the incidence of DNA methylation between tumor and non-tumor tissues, and evaluated the clinicopathological significance of the DNA methylation in gastric carcinoma. The data was presented by an odds ratio (OR) with an accompanying 95% confidence interval (CI). We then generated forest plots calculated by fixed-effects or random-effects model. Results: This study enrolled a total of 201 studies (140 papers). Our analysis showed a higher frequency of methylation of the CpG islands in GC tissues compared to non-neoplastic tissues. Besides, the data demonstrated that polygene's aberrant promoter methylation might be linked to the initial development and progression of GC. Discussion: The genes with altered DNA methylation might serve as epigenetic biomarkers, providing a promising molecular diagnostic and prognostic tool for human GC. However, our findings need further evaluation in large randomized controlled trials.

Self-Healable and Recyclable Dual-Shape Memory Liquid Metal-Elastomer Composites.

Liquid metal (LM)-polymer composites that combine the thermal and electrical conductivity of LMs with the shape-morphing capability of polymers are attracting a great deal of attention in the fields of reconfigurable electronics and soft robotics. However, investigation of the synergetic effect between the shape-changing properties of LMs and polymer matrices is lacking. Herein, a self-healable and recyclable dual-shape memory composite, comprising an LM (gallium) and a Diels-Alder (DA) crosslinked crystalline polyurethane (PU) elastomer, is reported. The composite exhibits a bilayer structure and achieves excellent shape programming abilities, due to the phase transitions of the LM and the crystalline PU elastomers. To demonstrate these shape-morphing abilities, a heat-triggered soft gripper, which can grasp and release objects according to the environmental temperature, is designed and built. Similarly, combining the electrical conductivity and the dual-shape memory effect of the composite, a light-controlled reconfigurable switch for a circuit is produced. In addition, due to the reversible nature of DA bonds, the composite is self-healable and recyclable. Both the LM and PU elastomer are recyclable, demonstrating the extremely high recycling efficiency (up to 96.7%) of the LM, as well as similar mechanical properties between the reprocessed elastomers and the pristine ones.

Shape memory polyurethane potentially used for vascular stents with water-induced stiffening and improved hemocompatibility.

Shape memory polymers (SMPs) with multiple functionalities have great potential in implantable biomedical devices, especially vascular stents. However, stents made of SMPs are generally faced with the problem of insufficient radial support due to the sharp decline of the modulus after shape recovery. Therefore, it is necessary to improve the modulus of SMPs after opening the narrow part by other means. In this study, the novel SMPs available for vascular stents were developed with impressive water-induced stiffening when shape recovered in a physiological environment. Herein, a series of shape memory polyurethanes (SMPUs) containing full hard segments on the main chains and bearing hydrophilic tertiary amine soft segments on the side chains were synthesized. When immersed in water, the soft segments were dramatically separated from the hard segments, which were aggregated more to form densely packed hard domains with stronger hydrogen bonding and higher crystallinity. Both Young's modulus and the shape recovery ratio were thus promoted due to the segmental rearrangement in water. At the same time, hydrophilic side chains migrated to the surface driven by the segmental rearrangement in water, which promotes the adhesion and growth of vascular endothelial cells and inhibits the activation of the coagulation system. The ingenious structural design provided SMPUs with adequate mechanical strength and hemocompatibility to qualify for potential applications in self-expanding vascular stents.

Conformally Adhesive, Large-Area, Solidlike, yet Transient Liquid Metal Thin Films and Patterns via Gelatin-Regulated Droplet Deposition and Sintering.

Adhesion and spreading of liquid metals (LMs) on substrates are essential steps for the generation of flexible electronics and thermal management devices. However, the controlled deposition is limited by the high surface tension and peculiar wetting and adhesion behavior of LMs. Herein, we introduce gelatin-regulated LM droplet deposition and sintering (GLMDDS), for the upscalable production of conformally adhesive, solidlike, yet transient LM thin films and patterns on diverse substrates. This method involves four steps: homogeneous deposition of LM microdroplets, gelation of the LM-gelatin solution, toughening of the gelatin hydrogel by solvent displacement, and peeling-induced sintering of LM microdroplets. The LM thin film exhibits a three-layer structure, comprising an LM microdroplet-embedded tough organohydrogel adhesion layer, a continuous LM layer, and an oxide skin. The composite exhibits high stretchability and mechanical robustness, conformal adhesion to various substrates, high conductivity (4.35 × 105 S·m-1), and transience (86% LM recycled). Large-scale deposition (i.e., 5.6 dm2) and the potential for patterns on diverse substrates demonstrate its upscalability and broad suitability. Finally, the LM thin films and patterns are applied for flexible and wearable devices, i.e., pressure sensors, heaters, human motion tracking devices, and thermal management devices, illustrating the broad applicability of this strategy.

Photodynamic Therapy in Combination with Chemotherapy, Targeted, and Immunotherapy As a Successful Therapeutic Approach for Advanced Gastric Adenocarcinoma: A Case Report and Literature Review.

Objective: To explore the efficacy of photodynamic therapy combined with chemotherapy, targeted therapy, and immunotherapy in poorly differentiated gastric adenocarcinoma (GAC). Background: Advanced GAC has high malignancy and mortality rate. To date, no study has applied photodynamic treatment (PDT) combined with chemo-, targeted, and immunotherapy to treat this cancer. Patient and methods: Clinical data of a patient diagnosed with poorly differentiated GAC admitted to the department of oncology of the Lanzhou University Second Hospital were retrospectively analyzed. The patient underwent four PDT procedures combined with chemo-, targeted, and immunotherapy. Results: A 72-year-old male patient received combination therapy of PDT. This treatment resolved the cancerous tissues and levels of tumor markers. There was no recurrence and metastasis during a 7-month follow-up. Conclusions: Combination therapy of PDT can effectively treat tumors and may be a method suitable for elderly patients with advanced GAC.

Solution-processable, soft, self-adhesive, and conductive polymer composites for soft electronics.

Soft electronics are rising electronic technologies towards applications spanning from healthcare monitoring to medical implants. However, poor adhesion strength and significant mechanical mismatches inevitably cause the interface failure of devices. Herein we report a self-adhesive conductive polymer that possesses low modulus (56.1-401.9 kPa), high stretchability (700%), high interfacial adhesion (lap-shear strength >1.2 MPa), and high conductivity (1-37 S/cm). The self-adhesive conductive polymer is fabricated by doping the poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) composite with a supramolecular solvent (ß-cyclodextrin and citric acid). We demonstrated the solution process-based fabrication of self-adhesive conductive polymer-based electrodes for various soft devices, including alternating current electroluminescent devices, electromyography monitoring, and an integrated system for the visualization of electromyography signals during muscle training with an array of alternating current electroluminescent devices. The self-adhesive conductive polymer-based electronics show promising features to further develop wearable and comfortable bioelectronic devices with the physiological electric signals of the human body readable and displayable during daily activities.

Synthesis Antifreezing and Antidehydration Organohydrogels: One-Step In-Situ Gelling versus Two-Step Solvent Displacement.

Organohydrogels with distinct antifreezing and antidehydration properties have aroused great interest among researchers, and various organohydrogels and organohydrogel-based applications have emerged recently. There are two popular synthesis strategies to prepare these antifreezing and antidehydration organohydrogels: the in-situ gelling and the solvent displacement strategies. Although both strategies have been widely applied, there is a lack of comparative study of these two strategies. In this work, to elucidate the comparative advantages of the two synthesis strategies, we studied and compared the mechanical and environmental tolerant properties of the organohydrogels synthesized from both strategies. The glycerol-based and ethylene glycol-based chemical polyacrylamide (PAAm) organohydrogel and the glycerol-based physical gelatin organohydrogel were synthesized and studied. Through the comparative study, we have found that the organohydrogels from different strategies with the same dispersion medium showed similar antifreezing and antidehydration properties but different mechanical properties. The mechanical properties of these organohydrogels are influenced by two opposite factors for each strategy: the enhanced physical interactions induced strengthening and solvent effect or swelling induced weakening. We hope this study may provide a better understanding of the synthesis strategies of organohydrogels and provide a valuable guide to choose the suitable synthesis strategy for each application.

A Self-Switchable Polymer Reactor for Controlled Catalytic Chemistry Processes with a Hyperbranched Structure.

A self-switchable polymer reactor with a hyperbranched structure for controlled catalytic chemistry processes is reported. This polymer reactor was made of silver nanoparticles and a polymer carrier consisting of hyperbranched polyethylenimine and hydroxyethyl acrylate that behaved as thermally switchable domains. Below the transfer temperature, relatively strong catalytic reactivity was demonstrated due to the leading role of hydrophilic groups in the switchable domains, which opened access to the substrate for the packaged silver nanoparticles. In contrast, it showed weak catalysis at relatively high temperatures, reducing from the significantly increased hydrophobicity in the switchable domains. In this way, the polymer reactor displays controllable, tunable, catalytic activity based on this approach. This novel design opens up the opportunity to develop intelligent polymer reactors for controlled catalytic processes.

Monodisperse polystyrene microspheres by dispersion copolymerization of styrene and other vinyl comonomers: characterization and protein adsorption properties.

Dispersion polymerization is a very attractive method for preparing micron-size monodisperse polymeric microspheres. The applications of microspheres have been greatly extended by using comonomers. In the present study, five kinds of polystyrene microspheres of 4-6 microm in diameters bearing different surface functional groups were synthesized by copolymerization of styrene and various vinyl comonomers. Their surface physicochemical characteristics were examined, including average particle size and size distribution, concentration of surface functional groups, as well as hydrophobicity. Concentration of FT-IR spectra of different samples were also discussed. The effects of microspheres' surface physicochemical properties on the isotherms of adsorption and chemisorption of BSA were determined. The results show that microspheres bearing different surface function groups have different capacity of protein adsorption. Besides, since the protein adsorption behaviors were more complex than the ideal adsorption model, the isotherms could not fit Freundlich model very well. Possible reasons were discussed. Knowledge gained from these results may be utilized for rational design of carriers of receptors and antibodies used in solid-phase immunoassay, especially Scintillation proximity assay in High-throughput Screening.

Core/shell particles containing 3-(methacryloxypropyl)-trimethoxysilane in the shell: synthesis, characterization, and application.

In comparison to the corresponding single-component counterparts, core/shell particles are widely used due to their better physical and chemical properties. The surface properties of core/shell particles evidently play an important role in the process of application. It is easy to deduce that surface properties mostly depend on the properties of the component in the shell. Therefore, desirable materials of shell are very significant for the study of composite materials, especially in core/shell field. It is well known that polysiloxane has excellent properties, such as the water repellency, high flexibility, low surface energy, and biocompatibility. Its application, however, is limited due to poor cohesiveness and poor film-forming properties. Recently, much endeavor has been made to overcome such flaws. It is found that polyacrylate is commonly considered for its good cohesiveness and excellent film-forming property. The combination of polysiloxane and polyacrylate has been shown to be important in the composite material field, especially as core/shell particles. Unfortunately, their hydrophobicity is considerably different and thus, the core/shell particles consisting of polyacrylate (PA)/polysiloxane (PSi) are hard to prepare by general seeded emulsion polymerization, and are also scarcely available in the literature. In this study, the new core/shell PA/PSi particles with poly(butyl methacrylate) (PA) as the core and poly(3-(methacryloxypropyl)-trimethoxysilane) (PSi) as the shell were prepared by dispersion polymerization under the kinetically controlled conditions. The characterization of the particles by TEM, DSC, particle size analyzer as well as static contact angle confirmed the formation of core/shell structure. The application of core/shell (PA/PSi) particles also has been considered and discussed here.TEM micrographs of core/shell (PA/PSi) particles.

Covalent immobilization of glucose oxidase onto poly(styrene-co-glycidyl methacrylate) monodisperse fluorescent microspheres synthesized by dispersion polymerization.

In this study, micron-sized poly(styrene-co-glycidyl methacrylate) (PSt-GMA) fluorescent microspheres of 5.1microm in diameter were synthesized via dispersion polymerization of styrene and glycidyl methacrylate in the presence of 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), which provided surface functional groups for covalent immobilization of enzymes. In an effort to study the biocompatibility of the microspheres' surface, glucose oxidase and beta-d-(+)-glucose were selected as a catalytic system for enzymatic assays. A colorimetric method was adopted in evaluating enzymatic activity by introducing horseradish peroxidase (HRP). Both the immobilization amount and the apparent activity of immobilized glucose oxidase from Aspergillus niger (GOD) were determined at different conditions. The results show that the immobilized enzymes retained approximately 28 to 34% activity, as compared with free enzymes, without pronounced alteration of the optimum pH and temperature. Kinetics studies show that the corresponding values of K(m) and V(max) are 23.2944 mM and 21.6450M/min.mg GOD for free enzymes and 35.1780 mM and 15.4799M/min.mg GOD for immobilized enzymes. The operational stability studies show that immobilized GOD could retain nearly 50% initial activity after being washed 20 times. The results suggest that the resultant PSt-GMA fluorescent microspheres provide a suitable surface for covalent immobilizing biomolecules; therefore, they have the potential of being used in fluorescence-based immunoassays in high-throughput screening or biosensors.