Chromatographic studies of mitomycin C degradation in albumin microspheres

Serum albumins and polylactic acid (PLA) have been used as bioerodable polymers in the preparation of drug-containing microspheres for parenteral drug delivery. The albumin microsphere may be prepared via either chemical cross-linking or heat denaturation of the protein. Heat-denatured albumin microspheres containing mitomycin C (MMC) have been used in pre-clinical and clinical investigations. Due to the high reactivity of MMC as a bifunctional alkylating agent, a study on the stability of MMC in the albumin and PLA microspheres has been carried out using a high-performance liquid chromatographic (HPLC) method. Human serum albumin (HSA) microspheres were prepared using an emulsion method via either heat denaturation at 120 or 170 degrees C or the use of 0.5 M biacetyl as a cross-linking agent. The PLA microspheres were prepared by an emulsion method at 55 degrees C. HPLC analysis of the HSA microspheres showed that about 37% of MMC was converted to 2,7-diaminomitosene derivatives in microspheres prepared by heat denaturation at 120 degrees C. The degradation increased to 82% when the microspheres were prepared with a denaturation temperature of 170 degrees C. The use of biacetyl as a cross-linking agent in the preparation of HSA microspheres resulted in a complete degradation of the incorporated MMC. Biacetyl was found to interact with MMC leading to the formation of 7-aminomitosene derivatives. In contrast to the albumin system, MMC may be incorporated into PLA microspheres without degradation.     

Incorporation of water-soluble drugs in PLGA microspheres

Poly(lactide-co-glycolide) (PLGA) microspheres containing blue dextran, as a model of water-soluble drugs, were prepared from w₁/o/w₂ emulsions by using a microhomogenizer and a solvent evaporation method. Effects of preparation conditions, such as, concentration of poly(vinyl alcohol) (PVA) in w₂ phase, viscosity of inner soluble water phase, volume ratio of oil phase to w₁ phase in primary emulsion, PLGA concentration in oil phase, and molecular weight or composition of PLGA, upon the properties of PLGA microspheres containing water-soluble drugs were examined. Concentration of poly(vinyl alcohol) (PVA), the dispersant dissolved in w₂ phase of secondary emulsion did not show any effects on the final particle size. On the other hand, volume ratio of oil phase to water one in primary emulsion affected the final particle size, which seemed to be related to the local PLGA concentration in w₁/o emulsions. That is, the particle size increased as the volume ratio of w₁ phase against oil phase, w₁/o (v/v), increased. The loading efficiency, however, was not affected by the volume ratio of w₁/o (v/v), but affected by blue dextran concentration in w₁ phase. Higher loading efficiency was observed in PLGA microspheres prepared from w₁ phase containing lower concentration of blue dextran. Blue dextran solution (inner water phase) with the lower viscosity may result in the lower leakage ratio of blue dextran during the preparation procedure. Increases in concentration and molecular weight of PLGA made particle size larger.     

Polycarbonate microspheres containing mitomycin C and magnetic powders as potential hepatic carcinoma therapeutics

The polycarbonate copolymer poly(trimethylene carbonate-co-5,5-dimethyl trimethylene carbonate) (P(TMC-co-DTC)) was synthesized by the polymerization of trimethylene carbonate (TMC) and 5,5-dimethyl trimethylene carbonate (DTC) using tin (II) 2-ethylhexanoate [Sn(Oct)(2)] as a catalyst. In vitro degradation tests indicated this polycarbonate copolymer degraded slowly in phosphate buffer saline solution (PBS, 0.1 mol/L, at 37°C). Magnetic polymer microspheres (MMC-PC-M) generated from the P(TMC-co-DTC) copolymer and containing Fe(3)O(4) magnetic ultrafine powders and an anticancer drug, mitomycin C (MMC) were prepared by a solvent evaporation technique. These anticancer magnetic polycarbonate microspheres showed strong magnetic responsiveness and high MMC loading capacity. In vitro drug release studies indicated that these microspheres sustained steady release rates of MMC in PBS. In vitro cytotoxicity assays demonstrated the microspheres were strongly inhibitory to human hepatic carcinoma (Bel-7204) cells. In vivo site-specific therapy in nude mice with human hepatic carcinoma indicated that the microspheres possessed markedly high antitumor activity against human hepatic carcinoma (Bel-7204).     

Preparation of Fe3O4@SiO2@layered double hydroxide core-shell microspheres for magnetic separation of proteins

Three-component microspheres containing an SiO(2)-coated Fe(3)O(4) magnetite core and a layered double hydroxide (LDH) nanoplatelet shell have been synthesized via an in situ growth method. The resulting Fe(3)O(4)@SiO(2)@NiAl-LDH microspheres display three-dimensional core-shell architecture with flowerlike morphology, large surface area (83 m(2)/g), and uniform mesochannels (4.3 nm). The Ni(2+) cations in the NiAl-LDH shell provide docking sites for histidine and the materials exhibit excellent performance in the separation of a histidine (His)-tagged green fluorescent protein, with a binding capacity as high as 239 μg/mg. The microspheres show highly selective adsorption of the His-tagged protein from Escherichia coli lysate, demonstrating their practical applicability. Moreover, the microspheres possess superparamagnetism and high saturation magnetization (36.8 emu/g), which allows them to be easily separated from solution by means of an external magnetic field and subsequently reused. The high stability and selectivity of the Fe(3)O(4)@SiO(2)@NiAl-LDH microspheres for the His-tagged protein were retained over several separation cycles. Therefore, this work provides a promising approach for the design and synthesis of multifunctional LDH microspheres, which can be used for the practical purification of recombinant proteins, as well as having other potential applications in a variety of biomedical fields including drug delivery and biosensors.     

A new type of cation‐exchange polymeric microspheres with pendant methylenethiol groups

Synthesis and characterization of the new styrene microspheres with pendant methylenethiol groups are presented. At the first stage, the polymeric matrices were obtained by the suspension–emulsion polymerization of monomers: styrene (St) with 2,3‐(2‐hydroxy‐3‐methacryloyloxypropoxy)naphthalene (NAF.DM) or (bis[4(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]sulfide (BES.DM) or divinylbenzene (DVB). At the second stage, the modification of the sythesized matrices was performed as follows: the matrices were reacted with paraformaldehyde in the presence of hydrochloric acid forming chloromethyl derivatives. Next, by reaction with thiourea, a thiouronium salt was obtained, and then the hydrolysis with NaOH solution and acidification with HCl were carried out. Finally, microspheres with –CH₂SH groups on their surface were obtained. The –SH group content (elemental analysis), thermal properties (thermogravimetric analysis), Fourier transform infrared as well as the swelling characteristics of the functional microspheres were examined. The surface texture was also visualized by the atomic force microscopy (AFM) method. The obtained polymers were screened towards sorption of Cu(II) ions. It was found that a better correlation between the experimental Cu(II) uptake and the theoretical curves predicted by the Langmuir or Freundlich models is obtained in the case of the DVB–St–SH polymer. In the case of the BES.DM–St–SH and 2,3‐NAF–St–SH ones, the Freundlich model corresponded quite well to the experimental data. Copyright © 2013 John Wiley & Sons, Ltd.     

Magnetic microspheres for targeting of drugs

Magnetic microspheres were prepared from starch. The microspheres could be crosslinked with various agents, and drugs could be entrapped adsorbed, or covalently coupled to the microspheres.     

Effects of shell composition,dosage and alkali type on the morphology of polymer hollow microspheres

Polymer hollow microspheres were prepared by performing alkali treatment on the multilayer core/shell polymer latex particles containing carboxyl groups. Effects of the shell composition and dosage as well as alkali type on the morphology of the microspheres were investigated. Results showed that in comparison with acrylonitrile(AN) and methacrylic acid(MAA), using butyl acrylate(BA) as the shell co-monomer decreased the glass transition temperature(T_g) of shell effectively and was beneficial to the formation of uniform and big hollow structure. Along with the increase of the shell dosage, the alkali-treated microspheres sequentially presented porous and hollow morphology, and the size of microspheres increased, while the hollow diameter increased first and then decreased, and the maximum hollow ratio reached 39.5%. Furthermore, the multilayer core/shell microspheres had better tolerance to NH_3·H_2O than to NaOH. When the molar ratio of alkali to methacrylic acid(MR_(alkali/acid)) for Na OH ranged from 1.15 to 1.30 or MRalkali/acid for NH_3·H_2O ranged from 1.30 to 2.00, the regular polymer hollow microspheres could be obtained.     

Preparation and characterisation of thermoresponsive poly[(N-isopropylacrylamide-co-acrylamide-co-(hydroxyethyl acrylate)] microspheres as a matrix for the pulsed release of drugs

Despite the large number of publications and patents concerning pH/thermoresponsive polymers, few data are available concerning the preparation of thermoresponsive cross-linked microspheres from preformed polymers. Therefore, N-isopropylacrylamide-co-acrylamide-co-(2-hydroxyethyl acrylate) copolymers were obtained as a new thermoresponsive material with a lower critical solution temperature (LCST) around 36 degrees C, in phosphate buffer at pH 7.4, and with a cross-linkable OH group in their structure. The LCST value was determined both by UV spectroscopy and microcalorimetric analysis. These copolymers were solubilised in acidified aqueous solution below their LCST, dispersed in mineral oil, and transformed into stable microspheres by cross-linking with glutaraldehyde. The thermoresponsive microspheres were characterised by optical and scanning electron microscopy, degree of swelling, and water retention. The pore dimensions of the microspheres and the retention volumes of some drugs and typical compounds were evaluated at different temperatures by liquid chromatography. Indomethacin, as a model drug, was included in the microspheres by the solvent evaporation method. Finally, the influence of temperature and of temperature cycling on drug release was investigated.     

Controllable preparation of magnetic polymer microspheres with different morphologies by miniemulsion polymerization

Magnetic poly(styrene-co-acrylic acid-co-acrylamide) microspheres were prepared by water-in-oil-in-water (W/O/W) miniemulsion polymerization of monomers in the presence of Fe3O4 nanoparticles. The copolymerizable monomers of acrylic acid and acrylamide were used not only to modify the surfaces of the microspheres with functional groups, but also to act as viscosity regulators to control the morphology and size of these microspheres. It was experimentally observed that the surfaces of these microspheres were functionalized with NH2 groups produced by copolymerization, the morphologies (sphere, ringlike, and one-hole) of the microspheres were controlled by the concentration of copolymerizable monomers, and all samples prepared were superparamagnetic. The possible mechanism of formation of these magnetic microspheres is also discussed.     

青霉素G酰化酶在含环氧基团的顺磁性聚合物微球上的固定化（英文）

青霉素G酰化酶(PGA)是一种重要的工业生物催化剂,常用于以青霉素G为底物生产7-氨基去乙酰氧基头孢烷酸(7-ADCA)和6-氨基青霉烷酸(6-APA)等半合成β-内酰胺类抗生素.然而,PGA较差的稳定性和可重复使用性能限制了其在工业上的广泛应用.因此,将PGA固定在固体载体上是很有必要的,可以形成一种可重复使用的高性能的多相催化剂.用于生物酶固定化的良好载体应具备以下条件:(1)载体表面具有可用于与生物酶多点结合的高密度的官能团;(2)载体具有较大的比表面积以固定更多的生物酶.通常情况下,可以通过减小载体的粒径来增加其比表面积,然而,小粒径的载体很难从反应混合液中分离出来,造成固定化酶回收使用困难.为了将聚合物微球的优异固定化性能与磁性纳米粒子的独特顺磁性结合起来,我们制备了一种含环氧基团的顺磁性聚合物微球作为PGA的固定化载体.但由于Fe_3O_4纳米颗粒具有较高的表面能,在反相悬浮聚合反应过程中容易团聚成大颗粒,从而导致制备的顺磁性聚合物微球的磁体含量、表面形貌和粒径分布存在差异.此外,Fe_3O_4纳米颗粒与聚合反应单体之间的相容性不好,使得部分磁性颗粒不能很好地包埋于聚合物微球内部,影响固定化酶的活性和操作稳定性.本文以N,N′–亚甲基双丙烯酰胺为交联剂,以甲基丙烯酸缩水甘油酯和烯丙基缩水甘油醚为功能性单体,用反相悬浮聚合方法在SiO_2包覆的Fe_3O_4纳米颗粒表面成功制备出含环氧基团的顺磁性聚合物微球.用SEM,FT-IR,XRD,VSM和低温氮气吸附等手段对含环氧基团的顺磁性聚合物微球进行了表征.研究了SiO_2对Fe_3O_4纳米颗粒的包覆和Fe_3O_4/SiO_2纳米颗粒的数量对于固定化酶的初始活性和操作稳定性的影响.SiO_2在反相悬浮聚合过程中发挥重要作用,用SiO_2对Fe_3O_4纳米颗粒进行亲水性改性,有效改善了Fe_3O_4纳米颗粒与聚合反应单体的相容性,将其引入反相悬浮聚合体系中,可以制备得到球形度好、粒径分布均匀和超顺磁性的含环氧基团的顺磁性聚合物微球,其中当Fe_3O_4/SiO_2纳米颗粒的质量比为7.5%时制备的含环氧基团的顺磁性聚合物微球具有最好的PGA固定化性能.PGA通过其活性非必需侧链基团–氨基与顺磁性聚合物微球表面的环氧基团的共价结合来制备顺磁性固定化酶,该固定化PGA的初始活性为430 U/g(wet),在外加磁场的作用下容易回收使用,重复使用10次后可保留99%的初始活性,具有良好的热稳定性和酸碱稳定性,具有较好的工业应用前景.     

Photochemical construction of nanoporous polymer microspheres in Cu/Cu2O nanoparticle suspensions

Taking the poly(styrene-co-acrylamide) (P(St-AM)) as a model material, a novel two-step photochemical method was introduced to construct nanoporous polymer microspheres at room temperature. Under ultraviolet light irradiation, suspensions composed of Cu/Cu₂O nanoparticles were first prepared in an alcohol solution of acetylacetonate and benzophenone. Subsequently, the monomers were photopolymerized around the nanoparticles in the suspension-added precursor solution to form polymer–nanoparticle composite microspheres. Nanoporous polymer microspheres could then be obtained by removing the particles with acid. The products had been investigated by XRD, SEM, TEM, IR, DSC, and BET. Results showed the typical microspheres had diameters of 200~300?nm, and the specific areas and pore volume regularly varied with the quantity of the suspensions. By the optimum control, porous P(St-AM) microspheres with average pore size of 5.7?nm, pore volume of 0.18?cm³/g, and specific surface area of 123.54?m²/g could be obtained. The method represents a new, easily manipulated, cost-effective, and safe route for preparation of porous polymer microspheres using inorganic porogens.     

On-column tryptic mapping of proteins using metal-ion-chelated magnetic silica microspheres by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Peptide mapping analysis, utilizing an easily replaceable and regenerable on-column enzymatic microreactor with metal-ion-chelated adsorption of enzyme on magnetic silica microspheres, combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), was developed. Firstly, magnetic microspheres of small size and strong magnetism were prepared through solvothermal reaction. Thereafter, by introducing tetraethyl orthosilicate (TEOS), magnetic silica (MS) microspheres were formed. Trypsin could then be immobilized onto the MS microspheres based on the Lewis acid-base interaction through the divalent cation chelators such as iminodiacetic acid (IDA), which was chemically bound to the microspheres through the introduction of glycidoxypropyltrimethoxysilane (GLYMO). The trypsin-immobilized MS microspheres were then locally packed into the capillary by the application of a strong magnetic field using a magnet. The performance of the method was exemplified with digestion of bovine serum albumin for 5 min at 50 degrees C and the result was comparable to the 12 h in-solution digestion. The ability of regeneration of the prepared on-column microreactor and good reproducibility of microreactor before and after regeneration were also demonstrated.     

Preparation of magnetic core mesoporous shell microspheres with C18-modified interior pore-walls for fast extraction and analysis of phthalates in water samples

In this study, core-shell magnetic mesoporous microspheres with C18-functionalized interior pore-walls were synthesized through coating Fe(3)O(4) microspheres with a mesoporous inorganic-organic hybrid layer with a n-octadecyltriethoxysilane (C18TES) and tetraethyl orthosilicate (TEOS) as the silica source and cetyltrimethylammonia bromide (CTAB) as a template. The obtained C18-functionalized Fe(3)O(4)@mSiO(2) microspheres possess numerous C18 groups anchored in the interior pore-walls, large surface area (274.7 m(2)/g, high magnetization (40.8 emu/g) and superparamagnetism, uniform mesopores (4.1 nm), which makes them ideal absorbents for simple, fast, and efficient extraction and enrichment of hydrophobic organic compounds in water samples. Several kinds of phthalates were used as the model hydrophobic organic compounds to systematically evaluate the performance of the C18-functionalized Fe(3)O(4)@mSiO(2) microspheres in extracting hydrophobic molecules by using a gas chromatography-mass spectrometry. Various parameters, including eluting solvent, the amounts of absorbents, extraction time and elution time were optimized. Hydrophobic extraction was performed in the interior pore of magnetic mesoporous microspheres, and the materials had the anti-interference ability to macromolecular proteins, which was also investigated in the work. Under the optimized conditions, C18-functionalized Fe(3)O(4)@mSiO(2) microspheres were successfully used to analyze the real water samples. The results indicated that this novel method was fast, convenient and efficient for the target compounds and could avoid being interfered by macromolecules.     

A new type of monodisperse porous, hydrophilic microspheres with reactive chloroalkyl functionality: synthesis and derivatization properties

A seeded polymerization method based on a new functional monomer, 3-chloro-2-hydroxypropyl methacrylate (HPMA-Cl), was proposed for the synthesis of a new type of monodisperse porous, hydrophilic microspheres with reactive character. By applying the method, poly(3-chloro-2-hydroxypropyl methacrylate-co-ethylene dimethacrylate) (poly(HPMA-Cl-co-EDMA)) microspheres in the range of 4–7 μm, with specific surface areas between 2 and 146 m²/g, were obtained. The microspheres are hydrophilic in nature due to the hydroxyl groups and are easily derivatizable due to the reactive chloropropyl moiety. Ligands in the form of small molecules carrying hydrophobic alkyl or hydrophilic ion exchanger groups were covalently attached onto the microspheres via simple and one-pot reactions via their chloropropyl functionality. Using the same functionality, click chemistry and surface-initiated atom transfer radical polymerization were also applied for the generation of triazole ring and zwitterionic molecular brushes on the microspheres, respectively. Poly(HPMA-Cl-co-EDMA) microspheres seem to be a promising hydrophilic reactive material particularly for the synthesis of ion exchanger resins and chromatographic stationary phases.     

pH-Responsive hollow polymeric microspheres and concentric hollow silica microspheres from silica-polymer core-shell microspheres

Nearly monodispersed silica-poly(methacrylic acid) (SiO 2-PMAA) core-shell microspheres were synthesized by distillation-precipitation polymerization from 3-(trimethoxysilyl)propylmethacrylate-silica (SiO 2-MPS) particle templates. SiO 2-PMAA-SiO 2 trilayer hybrid microspheres were subsequently prepared by coating of an outer layer of SiO 2 on the SiO 2-PMAA core-shell microspheres in a sol-gel process. pH-Responsive PMAA hollow microspheres with flexible (deformable) shells were obtained after selective removal of the inorganic SiO 2 core from the SiO 2-PMAA core-shell microspheres by HF etching. The pH-responsive properties of the PMAA hollow microspheres were investigated by dynamic laser scattering (DLS). On the other hand, concentric and rigid hollow silica microspheres were prepared by selective removal of the PMAA interlayer from the SiO 2-PMAA-SiO 2 trilayer hybrid microspheres during calcination. The hybrid composite microspheres, pH-sensitive hollow microspheres, and concentric hollow silica microspheres were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) analysis.     

Hydrogel-shelled biodegradable microspheres for sustained release of encapsulants

Biodegradable microparticles are promising for the sustained release of encapsulated lipophilic drugs. In particular, the microparticles with uniform size show excellent linearity of cumulated release over time with minimized initial burst. Here, we encapsulate the biodegradable microparticles with a hydrogel shell to improve the controllability over the sustained release and suspension stability. With a capillary microfluidic device, monodisperse oil-in-water-in-oil (O/W/O) double-emulsion droplets are produced to have a toluene solution of polylactic acid (PLA) in the core and sodium alginate and calcium-ethylenediaminetetraacetic acid (EDTA) complex in the shell, whereas the continuous oil phase contains acetic acid. As the toluene evaporates, PLA consolidates to form a microsphere in the core. At the same time, acetic acid diffuses from the continuous phase to the water layer, which causes the dissociation of the Ca-EDTA complex and the gelation of alginate. The hydrogel-shelled PLA microspheres are transferred from the oil to an aqueous solution of calcium chloride, which further tightens the gel shell. The resulting core-shell microspheres show sustained release of encapsulants for extended periods as the hydrogel shell serves as a diffusion barrier. Moreover, the hydrogel shells prevent interparticle agglomeration and adhesion to the solid walls, securing high suspension stability during the injection.     

Preparation of copolymer microspheres of diethylene glycol dimethacrylate

Preparation of copolymer microspheres of diethylene glycol dimethacrylate (2G) with several comonomers by radiation-induced radical polymerization is described. Ethyl methacrylate (EMA), acrylamide, maleic anhydride, and styrene gave microspheres successively. The copolymerization resulted in gelation more easily than the 2G homopolymerization. The allowed ratio of copolymerization is up to about 0.4 as the mole fraction of comonomer for the solution containing 10 vol % 2G monomer. Copolymerization affected the size of microspheres by keeping its narrow distribution. The size of microspheres was increased by the copolymerization with EMA and styrene and, was decreased with acrylamide. The formation of microsphere strongly depends on the crosslinking ability of monomers. The crosslinking ability and reactivity in the copolymerization cause the change of the size of the microspheres. © 1992 John Wiley & Sons, Inc.     

Preparation of biodegradable polyesteramide microspheres

Biodegradable polyesteramide copolymer P(CL/AU) based on -caprolactone and 11-aminoundecanoic acid was synthesized by the melt polycondensation method. Polyesteramide (PEA) microspheres were prepared by a simple O/W emulsion solvent evaporation method. The effects of variations in preparation parameters (such as emulsifier concentration, polymer concentration, polymer solution adding rate, stirring rate, and whether vacuum was applied) were studied in detail. The obtained microsphere morphologies were observed using an optical microscope and via scanning electron microscopy (SEM). The particle size distribution was determined using a Malvern laser particle sizer. When the PEA microspheres were incubated in PBS saline, the particle size increased at first, and then decreased after a longer time period; the theory that this behavior was due to degradation of the microspheres was confirmed by SEM.     

Novel superparamagnetic core-shell molecular imprinting microspheres towards high selective sensing

Novel superparamagnetic core-shell imprinting microspheres (MCSIMs) were synthesized using magnetite microspheres with 350 nm diameter and 70 nm thickness silica gel to form core-shell Fe(3)O(4)/SiO(2) composite for template phenylephrine (Phen) recognition and high efficiency separation. Compared to the previous imprinting recognition, the main advantage of this strategy lies in two aspects: one is the high stability and monodispersity of the MCSIMs structure, the other is the use of superparamagnetic Fe(3)O(4)/SiO(2) microspheres as an immobilization matrix and separation tool, thus greatly simplifying time-consuming washing steps. The affinity and selectivity of the MCSIMs were monitored by QCM and electrochemistry measurements. Imprinting microspheres have a remarkable affinity to Phen over that of structurally related molecules, including DA, EP, Phe and Tyr. The relative binding selectivity for different analytes estimated from amperometric signals was Phen : DA : EP = 40 : 5 : 1. The MCSIMs sensor showed a high sensitivity (400 microA mM(-1)), short response time (reaching 98% within 10 s), and broad linear response range from 1 microM to 0.1 mM and low detection limit (0.1 microM). Additionally, the results of control experiments showed that only negligible signal was obtained for non-imprinting microspheres. This could be reasonably attributed to the unique surface pores, charges and especially the nature of the functional groups inside MCSIMs cavities.     

Mesoporous Au/TiO2 nanocomposite microspheres for visible-light photocatalysis

Mesoporous Au/TiO(2) nanocomposite microspheres have been synthesized by using a microemulsion-based bottom-up self-assembly (EBS) process starting from monodisperse gold and titania nanocrystals as building blocks. The microspheres had large surface areas (above 270 m(2) g(-1)) and open mesopores (about 5 nm), which led to the adsorption-driven concentration of organic molecules in the vicinity of the microspheres. Au nanoparticles, which were stably confined within the microspheres, enhanced the absorption over the broad UV/Vis/NIR spectroscopic range, owing to their strong surface plasmon resonance (SPR); as a result, the Au nanoparticles promoted the visible-light photo-induced degradation of organic compounds.