PS Microspheres Research Articles

Rhodamine 6G-PAH probes for heavy metal: Fluorescence detection, bioimaging, and solid-phase sensing application

Four rhodamine 6G-PAH probes with pyrene (R6G-Pyr), anthracene (R6G-Ant), acenaphthene (R6G-Acp) or phenanthrene (R6G-PA) as fluorophore were designed and synthesized for Hg(II) detection. Probe R6G-PA, which had the lowest detection limit of 0.84 nmol/L, displayed the best fluorescence performance as compared to the other three probes. This type of probe had good anti-interference properties against most common metal ions except Cu(II). Metal Cu(II) had a certain quenching effect on the fluorescence generated by Hg(II), with a minimum detection limit of 0.31 nmol/L (for R6G-Acp), indicating its potential practicability for Cu(II) detection. The structure-fluorescence relationship was discussed based on density functional theory (DFT) calculations, and R6G-PA + Hg(II), which had the minimum dihedral angle between polycyclic aromatic rings and rhodamine spiro ring, produced the strongest π-π accumulation and provided the brightest fluorescence. Probe R6G-PA was successfully employed for fluorescence detection of Hg(II) in biological samples. Its solid-phase sensor PS@R6G-PA was developed by immobilizing R6G-PA on PS microspheres for the determination of Hg(II) in water and food samples, with excellent reproducibility and fluorescence “on/off” response. The relative error of the spiked recovery rate was less than 10 %.

Silver coated PS microsphere array SERS microfluidic chip for pesticide detection

Carbendazim and acetamidine are pesticides that widely used to control pests and diseases in oilseed rape. In this paper, a rapid, accurate and reliable method was proposed for the detection of carbendazim and acetamidine with SERS microfluidic chip technology. Ag-ps(Polystyrene microspheres) microsphere SERS substrate was prepared by spin coating and magnetron sputtering deposition of Ag. The enhancement factor of prepared SERS substrate was 2.4 × 1010. The SERS detection working curves were well fitted and the linear parameters R2 were 0.987 and 0.994, respectively. The limit of detection was 0.01 mg/mL. The use of SERS microfluidic chip to detect carbendazim and acetamidine is expected to provide a way for the detection of pesticide residues in crops, which has broad application prospects in the field of food safety.

Preparation and Mechanical Properties of Core-Shell PS&CeO2 Composite Abrasive Particles.

Core-shell composite abrasive particles are a topic of great interest in surface finishing. It is important to explore the preparation technology and performance parameters associated with them. In this paper, a core-shell composite abrasive particle made of polystyrene and cerium oxide (PS&CeO2, CSPC), which is rigid on the outside and flexible on the inside, is proposed. The microstructure, physical phase characteristics, and mechanical properties of the inner core and composite abrasive particles are investigated. PS microspheres and CSPC composite abrasive particles with different structural features were prepared through a series of experiments, morphological observations, and physical and chemical characterization experiments. Their microstructures and physical phase properties were investigated. The indentation load curves of the PS microspheres and CSPC composite abrasive samples were measured by using an atomic force microscope. The analysis focused on the effects of various dimensional and structural parameters on the modulus of elasticity of both PS microspheres and CSPC composite abrasive particles. The analysis shows that the experimentally prepared PS microspheres have good dispersion, a smooth surface, and a uniform particle size distribution. The prepared CSPC composite abrasive particles are regular spheres with rough, rice-like surfaces, low modulus of elasticity, and overall nonrigid and soft elastic properties. The results of this paper can provide a guide for the preparation technology, performance regulation, and application of polymer microspheres and core-shell composite abrasive particles in CMP.

Cationic PS Microspheres Modified GO and its effect on the properties of SBR/BR Rubber Composite materials

Cationic PS Microspheres Modified GO and its effect on the properties of SBR/BR Rubber Composite materials

Triangular Au nanoparticle arrays based on flexible materials as temperature-sensitive SERS substrates

In this study, PS microspheres were used as masks to obtain tip-connected triangular Au nanoparticle arrays on the surface of Cu films by thermal evaporation. Then transferred to flexible polydimethylsiloxane (PDMS), triangular Au nanoparticle arrays (Au NPAs/PDMS) were obtained by increasing the temperature using concentrated stress to cause fracture at the junction. The prepared Au NPAs/PDMS was used as an active substrate for surface-enhanced Raman spectroscopy (SERS), and the Raman signal of probe molecule rhodamine 6G (R6G) was collected while the substrate was heated. Due to the thermal expansion of PDMS, the gap of Au NPAs/PDMS changes with increasing temperature, enabling dynamic SERS detection. When the temperature reaches 64 °C, the substrate achieves the optimal Raman enhancement with a low RSD value of 5.8 % and a detection limit of 10−8 M for R6G. Furthermore, we modified the substrate hydrophobic, and finally obtained a low concentration of 10−10 M, with an enhancement factor of 3.5 × 108, to achieve highly sensitive SERS signal detection. In addition, due to the high optical transmittance and flexibility, the PDMS can be well-fitted to the surface of the object, indicating the potential of the fabricated substrates for in-situ detection.

Ultrasensitive electrochemiluminescence sensor for the detection of synthetic cannabinoids based on perovskite as coreaction accelerator and light-scattering effects of photonic crystals

As is common knowledge, a strong electrochemiluminescence (ECL) signal is required to ensure the high sensitivity of trace target detection. Here, a dual signal amplification strategy by integrating of perovskite and photonic crystal was fabricated for quantitative synthetic cannabinoids (AB-PINACA) detection based on Zr-connected PTCA and TCPP (PTCA-TCPP) with excellent ECL performance as luminophores. On the one hand, the co-reaction accelerator perovskite (LaCoO3) improved the effective electroactive area of the electrode and promoted the decomposition of K2S2O8, resulting in a stronger ECL signal value. On the other hand, polystyrene inverse opal (PIOPCs) formed after the swelling of PS microspheres not only taken advantage of the light scattering effect and excellent catalytic property of photonic crystals to amplify the ECL signal, but also could be used as a binder to fix LaCoO3 and PTCA-TCPP on the electrode surface to generate unprecedented ECL response and stable ECL signals. Subsequently, the detection substance AB-PINACA was loaded on the electrode surface via the amide bond with the luminophores PTCA-TCPP, thus quenching the ECL signal, so as to realize the sensitive detection of synthetic cannabinoids. Under the optimal conditions, the proposed sensor achieved highly sensitive AB-PINACA detection with a dynamic range from 1.0 × 10−12 to 1.0 × 10−3 g/L and the detection limit was 1.1 × 10−13 g/L, which had great application potential in the detection of synthetic cannabinoids.

Simplified 3D hydrodynamic flow focusing for lab-on-chip single particle study

Accurately control of the position of a fluid and particle within lab-on-a-chip platform is a critical prerequisite for many downstream analysis processes, such as detection, trapping and separation, moving the sensing at the single-particle level. With the development of microfluidic fabrication technology, particle/cell focusing has shifted from two to three dimensions. 3D hydrodynamic focusing, which sorts and aligns the incoming cloud of particles so that they pass through the interrogation area one by one, enables new possibilities and breakthroughs in the single-cell analysis system. Despite the excellent results shown in literature, there is still a lack of a device that can simultaneously fulfilling the requirements of high throughput, compactness, high integrability, and ease of use operation to become a widely accepted work center for biomedical research and clinical applications. Here, we proposed a unique 3D flow focusing microfluidic device buried in fused silica substrate that potentially combines all this advantages. By designing a sample channel suspended inside a larger buffer channel, manufactured by exploiting the laser-assisted micromachine technique, a not size-dependent focusing capability is shown. A spatially and temporally stable central flow of a mixture of 15 μm and 6 μm PS particles to a 1 μm PS microsphere solution has been obtained with high accuracy. Finally, to test the achievable focusing resolution, the chip was tested for the detection of Escherichia Coli bacteria in water solution as proof of concept of biological application.

SiO2 Modification of Silicon Carbide Membrane via an Interfacial In Situ Sol-Gel Process for Improved Filtration Performance.

Silicon carbide (SiC) membrane has emerged as a promising class of inorganic ceramic membranes with many advantageous attributes and has been used for a variety of industrial microfiltration (MF) processes. The state-of-the-art industrial manufacturing of SiC membranes based on the particle sintering method can only achieve an average pore size that ranges from 40 nm to a few micrometers, which is still unsatisfactory for ultrafiltration (UF) applications. Thus, the pore size control of SiC membranes remains a focus of continuing study. Herein, we provide an in situ sol-gel modification strategy to tailor the pore size of SiC membranes by a superficial deposition of SiO2 onto the membrane surface and membrane pore channels. Our in situ sol-gel modification method is simple and effective. Furthermore, the physical characteristics and the filtration performance of the membrane can easily be controlled by the in situ reaction time. With an optimal in situ reaction time of 30 min, the average pore size of the membrane can be reduced from macropores (400 nm) to mesopores (below 20 nm), and the retention ability for 20 nm fluorescent PS microspheres can be improved from 5% to 93%; the resultant SiC/SiO2 composite membranes are imparted with water permeance of 77 L·m-2·h-1·bar-1, improved anti-protein-fouling properties, excellent performance, and anti-acid stabilities. Therefore, modified SiC/SiO2 membranes based on the in situ sol-gel process have great potential as UF membranes for a variety of industrial processes.

Effect of Microplastics on the Activity of Digestive and Oxidative-Stress-Related Enzymes in Peled Whitefish (Coregonus peled Gmelin) Larvae.

Microplastics (MPs) are emergent pollutants in freshwater environments and may impact aquatic organisms, including those of nutritional value. The specific activities of digestive and antioxidant enzymes can be used as good bioindicators of the potential effects of MPs on fish in case of waterborne MP contamination. In this study, we used fluorescent polystyrene microplastics (PS-MPs) to analyze the alterations in enzyme activities in larvae of Coregonus peled Gmelin (peled or Northern whitefish), one of the most valuable commercial fish species of Siberia. Our results indicate that peled larvae can ingest 2 µm PS microspheres in a waterborne exposure model. A positive correlation (rs = 0.956; p < 0.01) was found between MP concentration in water and the number of PS microspheres in fish guts, with no significant differences between 24 h and 6-day exposure groups. The ingestion of MPs caused alterations in digestive enzyme activity and antioxidant responses at the whole-body level. The presence of PS-MPs significantly stimulated (p < 0.05) the specific activity of α-Amylase and non-specific esterases in peled larvae after 24 h. However, a pronounced positive effect (p < 0.05) of MPs on the activity of pancreatic trypsine and bile salt-activated lipase was only found after 6 days of exposure compared to after 24 h. Intestinal membrane enzyme aminopeptidase N was also stimulated in the presence of PS-MPs after 6-day exposure. We also observed a significant increase in the specific activity of catalase in peled larvae after 6 days of exposure, which indicates the MP-induced modulation of oxidative stress. Taken together, these results highlight the potential impact of environmental MPs on northern commercial fish, their importance for estimating fish stocks, and the sustainability of freshwater ecosystems.

Nanotopography of Polystyrene/Poly(methyl methacrylate) for the Promotion of Patient Specific Von Willebrand Factor Entrapment and Platelet Adhesion in a Whole Blood Microfluidic Assay.

Platelet function testing is essential for the diagnosis of patients with bleeding disorders. Specifically, there is a need for a whole blood assay that is capable of analysing platelet behaviour in contact with a patient-specific autologous von Willebrand factor (vWF), under physiologically relevant conditions. The creation of surface topography capable of entrapping and uncoiling vWF for the support of subsequent platelet adhesion within the same blood sample offers a potential basis for such an assay. In this study, spin coating of polystyrene/poly (methyl methacrylate) (PS/PMMA) demixed solutions onto glass substrates in air has been used to attain surfaces with well-defined topographical features. The effect of augmenting the PS/PMMA solution with uniform 50 µm PS microspheres that can moderate the demixing process on the resultant surface features has also been investigated. The topographical features created here by spin coating under ambient air pressure conditions, rather than in nitrogen, which previous work reports, produces substrate surfaces with the ability to entrap vWF from flowing blood and facilitate platelet adhesion. The direct optical visualisation of fluorescently-labelled platelets indicates that topography resulting from inclusion of PS microspheres in the PS/PMMA spin coating solution increases the total number of platelets that adhere to the substrate surface over the period of the microfluidic assay. However, a detailed analysis of the adhesion rate, mean translocating velocity, mean translocation distance, and fraction of the stably adhered platelets measured during blood flow under arterial equivalent mechanical shear conditions indicates no significant difference for topographies created with or without inclusion of the PS microspheres.

Single-cell HER2 quantification via instant signal amplification in microdroplets

Accurate and ultrasensitive evaluation of human epidermal growth factor receptor 2 (HER2) protein is key to early diagnosis and subtype differentiation of breast cancer. Single-cell analyses to reduce ineffective targeted therapies due to breast cancer heterogeneity and improve patient survival remain challenging. Herein, we reported a novel droplet microfluidic combined with an instant cation exchange signal amplification strategy for quantitative analysis of HER2 protein expression on single cells. In the 160 μm droplets produced by a tapered capillary bundle, abundant Immuno-CdS labeled on HER2-positive cells were replaced by Ag + to obtain Cd2+ that stimulated Rhod-5N fluorescence. This uniformly distributed and instantaneous fluorescence amplification strategy in droplets improves sensitivity and reduces signal fluctuation. Using HER2 modified PS microsphere to simulate single cells, we obtained a linear fitting of HER2-modified concentration and fluorescence intensity in microdroplets with the limit detection of 11.372 pg mL−1. Moreover, the relative standard deviation (RSD) was 4.2-fold lower than the traditional immunofluorescence technique (2.89% vs 12.21%). The HER2 protein on SK-BR-3 cells encapsulated in droplets was subsequently quantified, ranging from 9862.954 pg mL−1 and 205.26 pg mL−1, equivalent to 9.795 × 106 and 2.038 × 105 protein molecules. This detection system provides a universal platform for single-cell sensitive quantitative analysis and contributes to the evaluation of HER2-positive tumors.

High performance isolation of circulating tumor cells by acoustofluidic chip coupled with ultrasonic concentrated energy transducer

The isolation of circulating tumor cells (CTCs) from whole blood is a challenging task. Although various studies on the separation of CTCs by acoustofluidic devices have been reported, difficulties still persist, such as the complicated equipment, high cost, and difficult operation. Those problems should be resolved urgently. Herein, we developed an acoustofluidic chip separation system coupled with an ultrasonic concentrated energy transducer (UCET) system for efficient separation of CTCs. In the separation system, the acoustically sensitive particles were pre-focused by inertial forces of the PDMS chip channel structure. Then, the particles with different sizes were separated by acoustic radiation forces (ARF). In this study, the circulating tumor cells was simulated (CTCs-like particles) by aminated mesoporous acoustically sensitive particles (MSN@AM) encapsulated carboxylate polystyrene microspheres (PS-COOH). Subsequently, efficient CTCs-like particles separation was achieved by the acoustofluidic chip coupling system. This study effectively separated polystyrene microspheres carrying acoustically sensitive particles (MSN@AM@PS-COOH). However, the MSNs agglomerates and PS microspheres without acoustically sensitive particles did not show phenomenon of separation. This method allows to efficiently separate 2 µm MSNs agglomerates，8.0–8.9 µm PS microspheres and 10–10.5 µm MSN@AM@PS-COOH particles. It is demonstrated that the CTCs-like particles show more sensitive response, longer moving distance, and more obvious separation effect at the condition of the low frequency traveling wave sound field (20 kHz from UCET). This system can maintain the same separation with reduced amount of reagents used for cancer detection. It may provide a reliable basis for sorting out CTCs efficiently from the whole blood of cancer patients.

Turning a polystyrene microsphere into a multimode light source by laser irradiation

Abstract Polystyrene (PS) is generally considered as a passive optical material that is transparent to light with wavelengths longer than 300 nm. In practice, PS micro- and nanospheres with uniform sizes are usually used to build photonic crystals based on self-assembly mechanism. Here, we demonstrate experimentally that PS microspheres supporting whispery gallery modes can be transformed into multimode light sources by laser irradiation. We show that a PS microsphere placed on a silica substrate can be lighted up when it is consecutively irradiated by using a 488-nm continuous wave laser beam with a pumping power above a threshold. Broadband luminescence emitted from the PS microsphere increases rapidly to a maximum value and decreases gradually with increasing irradiation time, implying the generation and degradation of a certain luminescent material upon laser irradiation. However, the PS microsphere is found to be damaged by high temperature based on morphology examination. By replacing the silica substrate with a thin silver film, the threshold laser power for lighting up a PS microsphere is dramatically reduced. More importantly, we can see enhanced luminescence intensities from the whispery gallery modes supported by the PS microsphere, which becomes an efficient multimode light source. Interestingly, the threshold laser power can be further lowered by inserting a molybdenum disulfide monolayer in between the PS microsphere and the silver film. As a result, the PS microsphere remains nearly unchanged except the formation of the luminescence material. Our findings open a new horizon for the interaction of polymer with laser light by exploiting the optical resonances supported by micro- and nanoparticles and pave the way for constructing photonic devices based on laser-induced luminescent materials in polymers.

Toxic effects of pristine and aged polystyrene microplastics on selective and continuous larval culture of acorn barnacle Amphibalanus amphitrite.

This study evaluates the toxicity of pristine (Unwashed) and aged, clean (Biofilm-) or fouled (Biofilm+), PS microspheres (3 µm,10 µm), using Washed particles as a reference material, on selective and continuous larval culture of Amphibalanus amphitrite. Exposure to 3 µm Unwashed and Biofilm+ particles for 24 h induced significant mortality (60 % and 57 % respectively) in stage II larvae. Stage II and VI nauplii showed greater uptake of 3 µm Biofilm- particles. Accumulative exposure to microplastics in continuous larval culture significantly affected the naupliar survival, particularly of stage III and IV. Cumulative mortality was > 70% after exposure to 3 µm Unwashed and 10 µm Biofilm+ particles. Unwashed particles with increasing concentration and aged particles with increasing size, delayed the development of nauplii to cyprids. Though,> 50% cyprids showed successful settlement however the highest concentration of 3 µm Biofilm+ microspheres inhibited the settlement and induced precocious metamorphosis in 9 % of the cyprids.

Noninvasive Optical Isolation and Identification of Circulating Tumor Cells Engineered by Fluorescent Microspheres.

Circulating tumor cells (CTCs) are rare, meaning that current isolation strategies can hardly satisfy efficiency and cell biocompatibility requirements, which hinders clinical applications. In addition, the selected cells require immunofluorescence identification, which is a time-consuming and expensive process. Here, we developed a method to simultaneously separate and identify CTCs by the integration of optical force and fluorescent microspheres. Our method achieved high-purity separation of CTCs without damage through light manipulation and avoided additional immunofluorescence staining procedures, thus achieving rapid identification of sorted cells. White blood cells (WBCs) and CTCs are similar in size and density, which creates difficulties in distinguishing them optically. Therefore, fluorescent PS microspheres with high refractive index (RI) are designed here to capture the CTCs (PS-CTCs) and increase the average index of refraction of PS-CTCs. In optofluidic chips, PS-CTCs were propelled to the collection channel from the sample mixture, under the radiation of light force. Cells from the collection outlet were easily identified under a fluorescence microscope due to the fluorescence signals of PS microspheres. This method provides an approach for the sorting and identification of CTCs, which holds great potential for clinical applications in early diagnosis of disease.

Highly effective anti-corrosion composite coatings enhanced by non-covalent functionalized boron nitride nanosheets via a facile latex approach

Boron nitride nanosheets (BNNSs)/polymer composite coatings with highly effective corrosion resistance have promising applications in metal surface protection. However, BNNSs tend to aggregate in waterborne polymer matrix, which degrades anticorrosion. Herein, a facile and effective method was developed to fabricate a stable latex containing non-covalently modified BNNSs through in situ polymerization of styrene in emulsion system, and waterborne polyurethane (WPU) composite coatings were sequentially constructed for the purpose of corrosion protection via latex blending. The developed composite coating (BNNSs@PS/WPU) exhibited a significantly improved impedance by 4 orders of magnitude after 28 days of immersion compared with pure WPU coating. Such outstanding anti-corrosion properties can be ascribed to the comprehensive action of BNNSs@PS composite latex, of which the PS microspheres can not only effectively prevent BNNSs from coalesce, but also act synergically with BNNSs that effectively retard the permeation of corrosive medium to the metal surface.

Holey Ti3C2 nanosheets based membranes for efficient separation and removal of microplastics from water

The accumulation of non-degradable microplastics (MPs) originated from the mass production and huge consumption of plastics of modern industry in the water environment has resulted in severe pollution problems globally. Herein, we report for the first time the preparation of holey Ti3C2Tx (h-Ti3C2Tx) membranes obtained by etching Co3O4 nanoparticles embedded on Ti3C2Tx nanosheets followed by simple vacuum filtration using polymeric membranes as supporting matrix for efficient removal of MPs from wastewater. The h-Ti3C2Tx nanosheets exhibit a planar porous structure which present nano-holes with an average hole-size of 25 nm in diameter, which facilitated the construction of membranes with better water flux for the separation of MPs. Using fluorescent PS (FP) microspheres of different diameters as microplastic models, the obtained h-Ti3C2Tx membranes exhibited extremely high MPs removal performance (up to 99.3% under our conditions). Moreover, a large water flux of 196.7 L h−1 m−2 k Pa−1 can be obtained, which can compete or be larger than that of most of the membranes composed of untreated two-dimension nanomaterials. Due to the physicochemical stability, tremendous large water reflux, and the high MPs removal efficiency of h-Ti3C2Tx membranes, there may be a great potential for practical applications in the separation and removal of various contaminants such as MPs or suspended solids from water.

Uptake of Cu2+ by unicellular microalga Chlorella vulgaris from synthetic wastewaters is attenuated by polystyrene microspheres

Aquatic and terrestrial ecosystems are receiving micro- and macro-plastic pollutants alarmingly from various anthropogenic activities. The complications caused by microplastics are largely unexplored and need substantial studies. In the current study, we investigated the repressive effects of negatively and positively charged polystyrene microspheres of two variable sizes (0.05 and 0.5 μm) on functioning of unicellular green microalgae. For the purpose, a pollution-resistant microalgal species was isolated and identified by 18 S rRNA gene sequencing as Chlorella vulgaris. The functioning of the pure-cultured microalgal cells was then assessed in terms of their better metal (Cu2+) uptake potential with and without the provision of PS microspheres. The algal cells up took Cu2+ significantly (90% at 75 mg/L) after 15 days of aerobic incubation. However, positively charged polystyrene microspheres remarkably affected the uptake of Cu2+ and it was comparatively reduced to almost 50%, while negatively charged microspheres couldn't influence the Cu2+ uptake potential of C. vulgaris. In addition, size of the microspheres insignificantly affected the metal uptake potential of the microalgae. Unveiled facts of this investigation will be helpful for designing economical and efficient remedial systems based on the in-situ implication of microalgae.

Particle counting based on high-order Fano resonance in an optofluidic microcavity.

We demonstrate particle counting based on high-order Fano resonance (FR) in an optofluidic microcavity. The high-order FR excited by a thin fiber taper can penetrate the liquid core of a microcapillary. An optical pulse is generated due to the resonant spectrum shift when a particle crosses the microcavity. Analogous to other methods, such a pulse can be used for particle counting. The sampled particles of PS microspheres and super-absorbent polymer broken beads are used for particle-counting experiments. All results confirm the feasibility of such a counting method.

Tuning filament composition and microstructure of 3D-printed bioceramic scaffolds facilitate bone defect regeneration and repair.

It is still a challenge to optimize the component distribution and microporous structures in scaffolds for tailoring biodegradation (ion releasing) and enhancing bone defect repair within an expected time stage. Herein, the core–shell-typed nonstoichiometric wollastonite (4% and 10% Mg-doping calcium silicate; CSiMg4, CSiMg10) macroporous scaffolds with microporous shells (adding ∼10 μm PS microspheres into shell-layer slurry) were fabricated via 3D printing. The initial mechanical properties and bio-dissolution (ion releasing) in vitro, and osteogenic capacity in vivo of the bioceramic scaffolds were evaluated systematically. It was shown that endowing high-density micropores in the sparingly dissolvable CSiMg10 or dissolvable CSiMg4 shell layer inevitably led to nearly 30% reduction of compressive strength, but such micropores could readily tune the ion release behaviour of the scaffolds (CSiMg4@CSiMg10 vs. CSiMg4@CSiMg10-p; CSiMg10@CSiMg4 vs. CSiMg10@CSiMg4-p). Based on the in rabbit femoral bone defect repair model, the 3D μCT reconstruction and histological observation demonstrated that the CSiMg4@CSiMg10-p scaffolds displayed markedly higher osteogenic capability than the other scaffolds after 12 weeks of implantation. It demonstrated that core–shell bioceramic 3D printing technique can be developed to fabricate single-phase or biphasic bioactive ceramic scaffolds with accurately tailored filament biodegradation for promoting bone defect regeneration and repair in some specific pathological conditions.