Polymer Microbeads Research Articles

Physical studies of chitosan/PEG loaded Fe2O3 nanoparticles microbeads as a based biodegradable material for radiation shielding

This work reports two different strategies for the formation of hybrid microbeads using chitosan and polyethylene glycol (PEG) as based biodegradable materials for radiation shielding. An organic–inorganic hydrogel was prepared by ionotropic gelation. During the in-situ loading, incorporating magnetic nanoparticles Fe2O3 into the polymer matrix, magnetic nanostructures, were entrapped in the polymer matrix during the physical cross-linking of the polymer with the physical cross-linker (sodium triphosphate). However, in case of post-loading mechanism the loaded nanoparticles favor the precipitation on the surface of the formed beads. We use different characterization techniques for our systems such as scanning electron microscopy (SEM), x-ray, infrared spectroscopy (XRD), and X-ray radiation shielding application. The results demonstrate that by incorporating nanostructured magnetic particles into the polymer matrix, the surface morphology based on the two processes allow the magnetic nanoparticles to be embedded or form an outer shell and precipitated on the surface of polymer microbeads. The values of μ for the hydrogels loaded with Fe2O3 by in-situ process have the larger values of the linear coefficient however, in case of post-loading process the values dramatically decrease in compare with the in-situ ones at the same tube voltage. The presented work recommended as a good mentor for radiation shielding.

Single-image phase retrieval for off-the-shelf Zernike phase-contrast microscopes.

Quantitative phase imaging (QPI), such as digital holography, is considered a promising tool in the field of life science due to its noninvasive and quantitative visualization capabilities without the need for fluorescence labeling. However, the popularity of QPI systems is limited due to the cost and complexity of their hardware. In contrast, Zernike phase-contrast microscopy (ZPM) has been widely used in practical scenarios but has not been categorized as QPI, owing to halo and shade-off artifacts and the weak phase condition. Here, we present a single-image phase retrieval method for ZPM that addresses these issues without requiring hardware modifications. By employing a rigorous physical model of ZPM and a gradient descent algorithm for its inversion, we achieve single-shot QPI with an off-the-shelf ZPM system. Our approach is validated in simulations and experiments, demonstrating QPI of a polymer microbead and biological cells. The quantitative nature of our method for single-cell imaging is confirmed through comparisons with observations from an established QPI technique conducted through digital holography. This study paves the way for transforming non-QPI ZPM systems into QPI systems.

Polymer bead size revealed via neural network analysis of single-entity electrochemical data.

Single-entity electrochemistry methods for detecting polymer microbeads offer a promising approach to analyzing microplastics. However, conventional methods for determining microparticle size face challenges due to non-uniform current distribution across the surface of a sensing disk microelectrode. In this study, we demonstrate the utility of neural network (NN) analysis for extracting the size information from single-entity electrochemical data (current steps). We developed fully connected regression NN models capable of predicting microparticle radii based on experimental parameters and current-time data. Once trained, the models provide near-real-time predictions with good accuracy for microparticles of the same size, as well as the average size of two different-sized microparticles in solution. Potential future applications include analyzing various bioparticles, such as viruses and bacteria of different sizes and shapes.

Retention and excretion of microplastics by Yellow Mealworm (Tenebrio molitor) larvae reared on an amino formaldehyde polymer microbeads contaminated substrate

Abstract Yellow mealworm (Tenebrio molitor L., TM), one of the main cultured insect species, is used for feed and food. Larval stages of this species can be reared on several substrates, including grains and industrial by-products. However, this species may potentially accumulate contaminants from the substrate, including microplastics (MPs), which may represent a potential hazard for its utilization in food chain. Evidences for plastic degradation by mealworms have been reported, while there are few information about the retention of microplastics in the body and tissues of this species. The aim of the present study was to assess whether TM larvae reared on a MPs-contaminated substrate were able to retain MPs in body tissues and to evaluate the retention and excretion rate after fasting for 24 and 48 hours. For this purpose, fluorescent amino formaldehyde polymer microbeads (1-5 μm) were used to simulate a MPs contamination in the substrate used for larvae rearing. A relevant concentration of MPs were found in the gut and were associated with ingested feed. However, microscopic analyses indicated that the gut acts as a simple transit site and a barrier towards MPs migration in tissues. A marked reduction of MPS content was highlighted in larvae after fasting, even though a 48-hours fasting period was not sufficient to completely depurate insect gut from MPs. Results obtained in the present study suggest that the polymer microbeads used are recalcitrant to digestion by TM larvae, and show the relevant ability of depuration from MPs of this species. Taken together the results showed the suitability of TM to be reared on MPs contaminated substrates since larvae survival and growth resulted not hampered by the MPs presence and open cues on the fasting period able to completely depurate insect body from MPs residues.

Effect of pore size on the flexural strength of porous silicon carbide ceramics

Porous silicon carbide (SiC) ceramics with three different pore sizes (∼7, ∼45, and ∼98 μm) and three different porosities (∼40 %, ∼54 %, and ∼63 %) were prepared from mixtures of SiC, polysiloxane, boron carbide, phenolic resin, and polymer microbeads to investigate the effect of the pore size of porous SiC ceramics on their flexural strength. As the pore size increased from ∼7 to ∼98 μm, the flexural strength decreased from 116.3 to 80.8 MPa at a constant porosity of 40 %, owing to the increased defect size. The typical flexural strengths of porous SiC ceramics fabricated using ∼8 and ∼100 μm templates were 84.9 and 60.6 MPa respectively, at 54 % porosity; the flexural strengths were 58.7 and 43.9 MPa, respectively, at 63 % porosity. These results suggest that depending on the application, the mechanical properties of porous SiC ceramics can be successfully tuned by adjusting their pore size and porosity.

Free radical copolymerization of β-Myrcene by suspension process

In this study, for the first time, synthesis of polymer microbeads from β-myrcene (My) and 1,4-butanediol dimethacrylate (BDDMA) by suspension copolymerization is described. Free radical copolymerization of My and BDDMA has been either photo- or thermally initiated. In both systems influence of monomer composition has been investigated by varying the ratio of My between 10 and 90 vol% in the oil phase composition. My-BDDMA based microspheres have been synthesized successfully via both thermally initiated and photoinitiated suspension copolymerization process. Particle morphology, size and distribution of the microbeads has remarkably influenced by monomer composition and initiation step of the polymerization process. Photoinitiated copolymerization has resulted in a decrease in particle size and yielded quite narrow particle size distributions compared to thermally initiated copolymerization. The average molecular weight between cross-links (Mc), and cross-linking density (ν), calculated by using the Flory-Rehner Theory, has confirmed the significant influence of monomer composition and initiation step on the cross-linking.

Encapsulation of Cadmium-Free InP/ZnSe/ZnS Quantum Dots in Poly(LMA-co-EGDMA) Microparticles via Co-flow Droplet Microfluidics.

Quantum dots (QDs) are semiconductor nanocrystals that are used in optoelectronic applications. Most modern QDs are based on toxic metals, for example Cd, and do not comply with the European Restriction of Hazardous Substances regulation of the European Union. Latest promising developments focus on safer QD alternatives based on elements from the III-V group. However, the InP-based QDs lack an overall photostability under environmental influences. One design path of achieving stability is through encapsulation in cross-linked polymer matrices with the possibility to covalently link the matrix to surface ligands of modified core-shell QDs. The work focuses on the formation of polymer microbeads suitable for InP-based QD encapsulation, allowing for an individual protection of QDs and an improved processibility via this particle-based approach. For this, a microfluidic based method in the co-flow regime is used that consists of an oil-in-water droplet system in a glass capillary environment. The generated monomer droplets are polymerized in-flow into poly(LMA-co-EGDMA) microparticles with embedded InP/ZnSe/ZnS QDs using a UV initiation. They demonstrate how a successful polymer microparticle formation via droplet microfluidics produces optimized matrix structures leading to a distinct photostability improvement of InP-based QDs compared to nonprotected QDs.

Luminescence encoding of polymer microbeads with organic dyes and semiconductor quantum dots during polymerization

Luminescence-encoded microbeads are important tools for many applications in the life and material sciences that utilize luminescence detection as well as multiplexing and barcoding strategies. The preparation of such beads often involves the staining of premanufactured beads with molecular luminophores using simple swelling procedures or surface functionalization with layer-by-layer (LbL) techniques. Alternatively, these luminophores are sterically incorporated during the polymerization reaction yielding the polymer beads. The favorable optical properties of semiconductor quantum dots (QDs), which present broadly excitable, size-tunable, narrow emission bands and low photobleaching sensitivity, triggered the preparation of beads stained with QDs. However, the colloidal nature and the surface chemistry of these QDs, which largely controls their luminescence properties, introduce new challenges to bead encoding that have been barely systematically assessed. To establish a straightforward approach for the bead encoding with QDs with minimized loss in luminescence, we systematically assessed the incorporation of oleic acid/oleylamine-stabilized CdSe/CdS-core/shell-QDs into 0.5–2.5 µm-sized polystyrene (PS) microspheres by a simple dispersion polymerization synthesis that was first optimized with the organic dye Nile Red. Parameters addressed for the preparation of luminophore-encoded beads include the use of a polymer-compatible ligand such as benzyldimethyloctadecylammonium chloride (OBDAC) for the QDs, and crosslinking to prevent luminophore leakage. The physico-chemical and optical properties of the resulting beads were investigated with electron microscopy, dynamic light scattering, optical spectroscopy, and fluorescence microscopy. Particle size distribution, fluorescence quantum yield of the encapsulated QDs, and QD leaking stability were used as measures for bead quality. The derived optimized bead encoding procedure enables the reproducible preparation of bright PS microbeads encoded with organic dyes as well as with CdSe/CdS-QDs. Although these beads show a reduced photoluminescence quantum yield compared to the initially very strongly luminescent QDs, with values of about 35%, their photoluminescence quantum yield is nevertheless still moderate.

Anionic Dye Removal Using a Date Palm Seed-Derived Activated Carbon/Chitosan Polymer Microbead Biocomposite.

The discharge of textile wastewater into aquatic streams is considered a major challenge due to its effect on the water ecosystem. Direct blue 78 (DB78) dye has a complex structure. Therefore, it is difficult to separate it from industrial wastewater. In this study, carbon obtained from the pyrolysis of mixed palm seeds under different temperatures (400 °C and 1000 °C) was activated by a thermochemical method by using microwave radiation and an HCl solution in order to improve its adsorption characteristics. The generated activated carbon was used to synthesize a novel activated carbon/chitosan microbead (ACMB) for dye removal from textile wastewater. The obtained activated carbon (AC) was characterized by a physicochemical analysis that included, namely, particle size, zeta potential, SEM, EDX, and FTIR analyses. A series of batch experiments were conducted in terms of the ACMB dose, contact time, pH, and activated carbon/chitosan ratios in synthetic microbeads for enhancing the adsorption capacity. A remarkable improvement in the surface roughness was observed using SEM analysis. The particle surface was transformed from a slick surface with a minor-pore structure to a rough surface with major-pore structure. The zeta potential analysis indicated a higher improvement in the carbon surface charge, from −35 mv (before activation) to +20 mv (after activation). The adsorption tests showed that the dye-removal efficiency increased with the increasing adsorbent concentration. The maximum removal efficiencies were 97.8% and 98.4% using 3 and 4 g/L of AC400°C MB-0.3:1 and AC1000°C MB-0.3:1, respectively, with initial dye concentrations of 40 mg/L under acidic conditions (pH = 4–5), and an optimal mixing time of 50 min. The equilibrium studies for AC400°C MB-0.3:1 and AC1000°C MB-0.3:1 showed that the equilibrium data best fitted to the Langmuir isothermal model with R2 = 0.99. These results reveal that activated carbon/chitosan microbeads are an effective adsorbent for the removal of direct blue 78 dye and provide a new platform for dye removal.

A Review on various methods for the Cross-linking of Polymers

Cross-Linking the carbon atoms suffices to transform such material intoa superior material that may be resistant to temperature, pressure, corrosion, and that can be used in a variety of applications. Cross Linking is a stabilization process in polymer chemistry which leads to multidimensional extension of polymeric chain resulting in network structure. Cross-link is a bond which links one polymer chain to other. It can be ionic or covalent. Cross Linking changes a liquid polymer into ‘solid’ or ‘gel’ by restricting the ability of movement. When polymer chains are linked together by cross-links, they lose some of their ability to move as individual polymer chains. A liquid polymer (where the chains are freely flowing) can be turned into a ‘solid’ or ‘gel’ by cross-Linking the chains together. Cross Linking increases the molecular mass of a polymer. Cross-linked polymers are important because they are mechanically strong and resistant to heat, wear and attack by solvents. Cross-link property has been used to improve the insolubility, mechanical strength, stiffness, and rigidity of polymer microbeads having potential applications in solid-phase synthesis, solid-phase extraction, and biomedical fields. Hydrogels represents a class of high-water content polymers with physical or chemical crosslinks. Their physical properties are similar to soft tissues. A popular approach to attaining controlled drug delivery from polymer-based systemsinvolves the use of cross-linkers. In order to improve the properties of polymers specific toothier applications, they can be modified by either physical cross-linkers (high pressure, irradiation) or chemical cross-linkers (glutraldehyde, genipin).Therefore, synthesis of polymer with desired cross-linker (hydrophilic/hydrophobic/rigid/flexible) and concentration of cross-linker (cross-link density) is an important.Polyethylene (PE) once cross linked is advantageously employed in the fabrication of blanket insulation for electrical and telephone wires, pipes for the transport of cold and hot liquids, prostheses for the human body. In the present review, chemical cross-Linking by free-radical, condensation, UV radiation, and small-molecule cross-Linking are discussed in details.

A Review on Various Methods for the Cross-linking of Polymers

Cross-Linking the carbon atoms suffices to transform such material intoa superior material that may be resistant to temperature, pressure, corrosion, and that can be used in a variety of applications. Cross Linking is a stabilization process in polymer chemistry which leads to multidimensional extension of polymeric chain resulting in network structure. Cross-link is a bond which links one polymer chain to other. It can be ionic or covalent. Cross Linking changes a liquid polymer into ‘solid’ or ‘gel’ by restricting the ability of movement. When polymer chains are linked together by cross-links, they lose some of their ability to move as individual polymer chains. A liquid polymer (where the chains are freely flowing) can be turned into a ‘solid’ or ‘gel’ by cross-Linking the chains together. Cross Linking increases the molecular mass of a polymer. Cross-linked polymers are important because they are mechanically strong and resistant to heat, wear and attack by solvents. Cross-link property has been used to improve the insolubility, mechanical strength, stiffness, and rigidity of polymer microbeads having potential applications in solid-phase synthesis, solid-phase extraction, and biomedical fields. Hydrogels represents a class of high-water content polymers with physical or chemical crosslinks. Their physical properties are similar to soft tissues. A popular approach to attaining controlled drug delivery from polymer-based systemsinvolves the use of cross-linkers. In order to improve the properties of polymers specific toothier applications, they can be modified by either physical cross-linkers (high pressure, irradiation) or chemical cross-linkers (glutraldehyde, genipin).Therefore, synthesis of polymer with desired cross-linker (hydrophilic/hydrophobic/rigid/flexible) and concentration of cross-linker (cross-link density) is an important.Polyethylene (PE) once cross linked is advantageously employed in the fabrication of blanket insulation for electrical and telephone wires, pipes for the transport of cold and hot liquids, prostheses for the human body. In the present review, chemical cross-Linking by free-radical, condensation, UV radiation, and small-molecule cross-Linking are discussed in details.

Exploring Sensitive Label-Free Multiplex Analysis with Raman-Coded Microbeads and SERS-Coded Reporters.

Suspension microsphere immunoassays are rapidly gaining attention in multiplex bioassays. Accurate detection of multiple analytes from a single measurement is critical in modern bioanalysis, which always requires complex encoding systems. In this study, a novel bioassay with Raman-coded antibody supports (polymer microbeads with different Raman signatures) and surface-enhanced Raman scattering (SERS)-coded nanotags (organic thiols on a gold nanoparticle surface with different SERS signatures) was developed as a model fluorescent, label-free, bead-based multiplex immunoassay system. The developed homogeneous immunoassays included two surface-functionalized monodisperse Raman-coded microbeads of polystyrene and poly(4-tert-butylstyrene) as the immune solid supports, and two epitope modified nanotags (self-assembled 4-mercaptobenzoic acid or 3-mercaptopropionic acid on gold nanoparticles) as the SERS-coded reporters. Such multiplex Raman/SERS-based microsphere immunoassays could selectively identify specific paratope–epitope interactions from one mixture sample solution under a single laser illumination, and thus hold great promise in future suspension multiplex analysis for diverse biomedical applications.

Sustainably closed loop recycling of hierarchically porous polymer microbeads for efficient removal of cationic dyes

Herein, we designed and fabricated a hierarchically porous crosslinked polymeric microbead (PCP) with high density of functional groups for selective adsorption of cationic dyes from water.

(Invited) Breathable, Stimuli-Responsive, and Self-Sealing Chemical Barrier Material Based on Selectively Superabsorbing Polymer

The occasional use of chemical warfare agents (CWAs) by rogue states in current conflicts provides a reminder that these hazards are a real threat. Although hazmat suits made of fully impermeable barrier materials provide an effective means of protecting against CWAs, they also inhibit evaporative cooling which can cause rapid hyperthermia. This conundrum has motivated a search for novel materials that allow water vapor but not CWA permeation. Here we show that, at least for aerosolized CWA, this can also be achieved using a highly breathable composite fabric that self-seals only when exposed to target chemicals. Our approach is based on the use of selectively superabsorbing polymer (SAP) microbeads that are dispersed on a highly breathable fabric. Many CWAs, especially nerve and blistering agents, have low vapor pressure and can only be dispersed as a “fog” from aerosolization. We show that upon contact with an example organic aerosol (o-xylene) the proposed SAP microbeads dispersed on a nylon mesh swell highly, seal pores, and inhibit passage of the microdroplets. In contrast, in normal conditions the SAP microbeads do not absorb or swell upon contactwith water and provide over 10 kg m−2 day−1 water permeation rate that is comparable to a cotton shirt. Figure 1

(Invited) Breathable, Stimuli-Responsive, and Self-Sealing Chemical Barrier Material Based on Selectively Superabsorbing Polymer

The persistent use of chemical warfare agents (CWAs) by rogue states in current conflicts provides a reminder that these hazards remain a real threat. Although hazmat suits made of fully impermeable barrier materials provide an effective means of protecting against CWAs, they also inhibit evaporative cooling which can cause rapid hyperthermia. This conundrum has motivated a search for novel materials that allow water vapor but not CWA permeation. Here we show that, at least for aerosolized CWA, this can be achieved using a highly breathable composite fabric that self-seals only when exposed to target chemicals. Our approach is based on the use of selectively superabsorbing polymer (SAP) microbeads that are dispersed on a highly breathable fabric. Many CWAs, especially nerve and blistering agents, have low vapor pressure and are typically dispersed as a “fog” via aerosolization. We show that upon contact with an example organic aerosol (o-xylene) the proposed SAP microbeads dispersed on a nylon mesh rapidly swell, seal pores in the material, and inhibit passage of the microdroplets. In contrast, the SAP microbeads do not swell on contact with water and provide a water vapor permeation rate of over 10 kg m− 2 day− 1, comparable to a cotton shirt.

Coherent Raman scattering imaging with a near-infrared achromatic metalens.

Miniature handheld imaging devices and endoscopes based on coherent Raman scattering are promising for label-free in vivo optical diagnosis. Toward the development of these small-scale systems, a challenge arises from the design and fabrication of achromatic and high-end miniature optical components for both pump and Stokes laser wavelengths. Here, we report a metasurface converting a low-cost plano–convex lens into a water-immersion, nearly diffraction-limited and achromatic lens. The metasurface comprising amorphous silicon nanopillars is designed in a way that all incident rays arrive at the focus with the same phase and group delay, leading to corrections of monochromatic and chromatic aberrations of the refractive lens, respectively. Compared to the case without the metasurface, the hybrid metasurface-refractive lens has higher Strehl ratios than the plano–convex lens and a tighter depth of focus. The hybrid metasurface-refractive lens is utilized in spectroscopic stimulated Raman scattering and coherent anti-Stokes Raman scattering imaging for the differentiation of two different polymer microbeads. Subsequently, the hybrid metalens is harnessed for volumetric coherent Raman scattering imaging of bead and tissue samples. Finally, we discuss possible approaches to integrate such hybrid metalens in a miniature scanning system for label-free coherent Raman scattering endoscopes.

Preparation of Poly(Ionic Liquid) Microbeads via Cooling-Assisted Phase Separation Method.

A simple and large-scale non-chemical preparation of uniform poly(ionic liquid) (PIL) microbeads via a cooling-assisted phase separation (CAPS) method is reported. For this method, PIL bulk is dissolved to form a saturated solution in a mixed solvent composed of good solvent and non-solvent at a relatively high temperature. Then, the uniform PIL microbeads are prepared by cooling the solution to room temperature or a lower temperature in the absence of stabilizer. The size of microbeads can be controlled by adjusting the preparation parameters, including PIL concentration, cooling rate, and agitation state. The scale of preparation can be up to 10g, and the yield of PIL microbeads is more than 70% or 88% when the solution is cooled to room temperature or 0°C, respectively. The formation mechanism of PIL microbeads is discussed by tracing the nucleation and growth process by the transmittance of light of the solution during cooling. The application of this CAPS method to other polymer microbeads preparation is finally discussed by choosing different good solvent and non-solvent.

Macromolecular Crowding Effect on the Activity of Liposome-Bound Alkaline Phosphatase: A Paradoxical Inhibitory Action.

The cytoplasm of a cell is extremely crowded, with 20-30% being large biomolecules. This crowding enforces a significant amount of the physical and chemical barrier around biomolecules, so understanding any biomolecular event within the cellular system is challenging. Unsurprisingly, enzymes show a diverse kind of catalytic behavior inside a crowded environment and thus have remained an area of active interest in the last few decades. The situation can become even more complex and exciting in the case of understanding the behavior of a membrane-bound enzyme (almost 25-30% of enzymes are membrane-bound) in such a crowded environment that until now has remained unexplored. Herein, we have particularly investigated how a membrane-bound enzyme (using liposome-bound alkaline phosphatase) can behave in a crowded environment comprising polymer molecule-like poly(ethylene glycol) (PEG) of different weights (PEG400, PEG4000, and PEG9000) and Ficoll 400. We have compared the activity using a polymer microbead conjugated enzyme and have found that liposome-bound alkaline phosphatase had much higher activity in crowded environments, showing the importance and superiority of soft-deformable particles (i.e., vesicles) over hard spheres in macro-molecularly crowded media. Interstingly, we have found a paradoxical behavior of inhibitors in terms of both their extent and pathway of inhibitory action. For instance, phosphates, known as competitive inhibitors in buffer, behave as uncompetitive inhibitors in liposome-bound enzymes in crowded media with an ∼5-fold less inhibitory effect, whereas phenyl alanine (an uncompetitive inhibitor in buffer) did not show any inhibitory potential when the enzyme was membrane-bound and in crowded media containing PEG9000 (30 wt %). Overall, this demonstration elucidates aspects of membrane-bound enzymes in crowded media in terms of both catalytic behavior and inhibitory actions and can lead to further studies of the understanding of enzymatic behavior in such complex crowded environments having a dampening effect in regular diffusive transport.

Statistic estimation of cell compressibility based on acoustophoretic separation data

We present a new experimental method that measures the compressibility of phenotype-specific cell populations. This is done by performing statistical analysis of the cell counts from the outlets of an acoustophoresis chip as a function of the increasing actuator voltage (i.e. acoustic energy density) during acoustophoretic separation. The theoretical separation performance curve, henceforth, Side-Stream Recovery (mathrm {SSR}), vs the piezo-actuator voltage (V) is derived by moment analysis of a one-dimensional model of acoustophoresis separation, accounting for distributions of the cell or microparticle properties and the system parameters (hydrodynamics, radiation force, drag enhancement, and acoustic streaming). The acoustophoretic device is calibrated with polymer microbeads of known properties by fitting the experimental mathrm {SSR} with the theoretical mathrm {SSR}, in which the acoustic energy density is considered proportional to the squared voltage, i.e. E_mathrm {ac}^{}=alpha ,V^2_{}. The fitting parameter alpha for the calibration procedure is the device effectivity, reflecting the efficiency in performing acoustophoretic microparticle displacement. Once calibrated, the compressibility of unknown cells is estimated by fitting experimental mathrm {SSR} cell data points with the theoretical mathrm {SSR} curve. In this procedure, the microparticle compressibility is the fitting parameter. The method is applied to estimate the compressibility of a variety of cell populations showing its utility in terms of rapid analysis and need for minute sample amounts.

A modular polymer microbead angiogenesis scaffold to characterize the effects of adhesion ligand density on angiogenic sprouting

Three-dimensional micro-physiological in vitro representations of human tissues and organs are emerging as important models of human pathophysiology and stand to make a significant impact on the process of drug discovery and development. An enduring need is to create microvascular networks within such 3D models, particularly for tissues with high metabolic demand such as the liver, pancreas, and the central nervous system. Here we report a facile approach to drive angiogenesis in nascent 3D culture models by embedding degradable hydrogel microbeads coated with induced pluripotent stem cell-derived endothelial cells (MB-iPSC-ECs) in a dense epithelial tissue. Specifically, we describe an approach to optimize microbead scaffold cues, independent of the external environment, by evaluating the iPSC-EC to microbead adhesion properties and how they influence the propensity of cells to both coat microbeads uniformly and undergo sprouting angiogenesis. We encapsulated MB-iPSC-ECs in PEG hydrogels, systematically varied the relative concentration of integrin-targeting peptide motifs in the microbead and surrounding environment, and found that an optimal microbead scaffold ligand regime of 0.1–0.25 mM promotes iPSC-EC monolayer formation and subsequent invasion into the synthetic matrix. We used these results to predict the regime of adhesion ligand required to promote angiogenesis of MB-iPSC-ECs in a co-culture hepatocarcinoma (HEPG2) microtissue model. This modular degradable microbead platform has the potential to promote angiogenic sprouting, which may ultimately support vascularization of a variety of cell-dense tissues.