Biomedical Engineering Reference
In-Depth Information
TABLE 7.3
Summary of Particle Manufacturing Techniques and Employed
Polymers
Process
Polymers
Emulsion polymerization
Poly(alkyl methacrylate)
Poly(alkyl cyanoacrylate)
Poly(styrene)
Poly(vinyl pyridine)
Poly(acrolein)
Interfacial polymerization
Poly(alkyl cyanoacrylate)
Poly(lysine) derivatives
Emulsifi cation evaporation
Poly(lactic acid)
Poly(lactide-
co
-glycolide)
Poly(β-hydroxybutyrate)
Ethyl cellulose
Solvent displacement
Poly(alkyl methacrylate)
Poly(lactic acid)
Poly(lactide-
co
-glycolide)
Poly(1-caprolactone)
Salting out
Cellulose acetate phthalate
Poly(alkyl methacrylate)
Ethyl cellulose
Poly(lactic acid)
Poly(lactide-
co
-glycolide)
Desolvation and denaturation
Albumin
Casein
Gelatin
Ethyl cellulose
Ionic gelation
Alginate
Chitosan
Carboxymethyl cellulose
methacrylic acid with PEG macromer was carried out using a photoinitiator in water. Pluronics-
based polymers were used to prevent the aggregation of these nanospheres and to render them
redispersion ability.
7.4.4.1.3 Suspension Polymerization
Water-insoluble monomer involves the use of stabilizers and monomer-soluble initiators. This feature
leads to the formation of polydisperse monomer droplets in water in the size of about 20-1000 μm
followed by polymerization and direct conversion of droplets into corresponding polymer particles
of approximately the same size. Skovby et al. described a suspension polymerization technique for
the preparation of methacrylic acid using hydroxyapatite and magnesium hydroxide as suspending
agents [135,136].
We have recently adopted a novel chitosan-based ionic gelation process for the preparation of
PMAA-based microparticles [137-139]. Methacrylic acid was polymerized in the presence of chito-
san in aqueous medium, and particles were obtained spontaneously during the polymerization with-
out the addition of any organic solvents and steric stabilizers. PMAA-CS particles displayed good
protein encapsulation effi ciency and demonstrated pH responsive release behavior at stimulated
gastric and intestinal pH. Application of these microparticles toward oral protein delivery was eval-
uated using insulin and bovine serum albumin (BSA) as model proteins.
