TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The organic catalytic material is an enzyme (preferably catalase, peroxidase, superoxide dismutase, carbonic anhydrase, cytochrome P450, alcohol dehydrogenase, aspartate aminotransferase, luciferase, hydrolase, glucose oxidase, glucose isomerase, trypsin, papain, protease, lipase, esterase, urease, cellulase, amylase, lactase, phytase, amidase, thermolysin, diacetyl reductase, or nitrile hydrolase).    TECHNOLOGY FOCUS - POLYMERS - Preferred Particles: The water-insoluble semi-permeable polymer and the aqueous solution or dispersion of the organic catalytic material are present in each semi-permeable particle at a weight ratio of at least 0.04-3.5. The semi-permeable particle further comprises an amphiphilic (low hydrophile-lipophile balance (HLB)) block copolymer that is disposed at the interface of the multiple discrete cavities and the continuous polymeric phase. Each semi-permeable particle has a mode particle size of at least 1-100 (preferably 2-40) mu m. The volume of the multiple discrete cavities in each semi-permeable particle is at least 10-60% of the total semi-permeable particle volume. The average discrete cavity size is at least 200 nm to 5 mu m. The semi-permeable particle further comprises a surface stabilizing material on the external particle surface; and colloidal or fumed silica on the external particle surface. Preferred Method: In (M1), after chemical reaction of the organic catalytic material with reactive chemical, the slurry of semi-permeable particles is reused by contacting the semi-permeable particles with same or different chemical reactant. Preferred Components: The water-insoluble semi-permeable polymer is selected from a polyester, polyamide, polyurethane, styrenic polymer, mono-olefin polymer, vinyl ester polymer, and acrylic polymer, vinyl ether polymer, vinyl ketone polymer, and aliphatic cellulose ester polymer. The cavity stabilizing hydrocolloid is selected from carboxymethyl cellulose (CMC), a gelatin or gelatin derivative, a protein or protein derivative, a hydrophilic synthetic polymer, a water-soluble microgel, a polystyrene sulfonate, poly(2-acrylamido-2-methylpropanesulfonate), and a polyphosphate. EXAMPLE - A first water phase (W1) was prepared using solution (40.3 g) of a carboxy methyl cellulose, sodium salt solution in water along with glucose oxidase solution (21.4 g) in phosphate buffer (50 mmolar, pH 6.0). The oil phase (O) was prepared using solution (36.5 g) of poly(caprolactone) in ethyl acetate, solution (12.1 g) of poly(ethylene oxide-co-b-caprolactone) in ethyl acetate, and ethyl acetate (153.0 g). To this oil phase was added to the W1 phase followed by mixing. The resulting water-in-oil (W1/O) emulsion was further homogenized at a pressure of 8000 psi. This water-in-oil emulsion was added to a second water phase (W2) comprising solution (13.7 g) of Nalco 1060 (RTM: colloidal silica) in water, a citrate/phosphate buffer (207 mmolar, pH 4, 419.8 g), and a solution (6.9 g) of poly(methyl amino ethanol) adipate (co-stabilizer) in water. The resulting mixture was stirred. The ethyl acetate was evaporated from the mixture at 40 degrees C under reduced pressure to yield semi-permeable particles containing glucose oxidase in the resulting discrete cavities. The resulting semi-permeable particles were washed on a glass frit funnel, and stored as a suspension (slurry) in phosphate buffer (50 mmolar, pH 6.0). The amount of protein encapsulated within the resulting 3-8 mu m semi-permeable particles was found to be 91 mu g/g (dry basis). The weight ratio of the water-insoluble semi-permeable polymer to the aqueous solution of the organic catalytic material was 0.26.