title: Production methodologies of polymeric and hydrogel particles for drug delivery applications.
abstract: BACKGROUND
  Polymeric particles are ideal vehicles for controlled delivery applications due to their ability to encapsulate a variety of substances, namely low- and high-molecular mass therapeutics, antigens or DNA. Micro and nano scale spherical materials have been developed as carriers for therapies, using appropriated methodologies, in order to achieve a prolonged and controlled drug administration.
  
  
  METHODS
  This paper reviews the methodologies used for the production of polymeric micro/nanoparticles. Emulsions, phase separation, spray drying, ionic gelation, polyelectrolyte complexation and supercritical fluids precipitation are all widely used processes for polymeric micro/nanoencapsulation. This paper also discusses the recent developments and patents reported in this field. Other less conventional methodologies are also described, such as the use of superhydrophobic substrates to produce hydrogel and polymeric particulate biomaterials.
  
  
  CONCLUSIONS
  Polymeric drug delivery systems have gained increased importance due to the need for improving the efficiency and versatility of existing therapies. This allows the development of innovative concepts that could create more efficient systems, which in turn may address many healthcare needs worldwide. The existing methods to produce polymeric release systems have some critical drawbacks, which compromise the efficiency of these techniques. Improvements and development of new methodologies could be achieved by using multidisciplinary approaches and tools taken from other subjects, including nanotechnologies, biomimetics, tissue engineering, polymer science or microfluidics.
authors.affiliation: University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, 3B’s Research Group-Biomaterials, Biodegradables and Biomimetics, Guimarães, Portugal.
authors.forename: Ana Catarina
authors.initials: AC
authors.lastname: Lima
authors.forename: Praveen
authors.initials: P
authors.lastname: Sher
authors.forename: João F
authors.initials: JF
authors.lastname: Mano
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods*; D004345:Drug Industry / Q000379:methods*; D004655:Emulsions; D005079:Excipients; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D044085:Microfluidics; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D005079:Excipients; D011108:Polymers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate