Table 1.
A summary of polymers that are commonly used for nano drug delivery targets.
| Polymer | Characteristics | Application |
|---|---|---|
| PLGA | One of the first and most commonly used polymers in drug delivery First used in the mid 1980s FDA approved Biocompatible Biodegradable |
Used for many drug delivery applications including: vaccination, cancer (Danhier et al., 2012) |
| PEG | A hydrophilic polymer Generally safe First used in the late 1960s |
Used as a coating material for nanoparticles to achieve more efficient drug delivery by extending the drug’s circulation time in the bloodstream; to avoid elimination by RES "stealthing" (Suk et al., 2016) |
| Poloxamer/ PEO-PPO-PEO | A block co-polymer Amphiphilic nature Its molecular weight can be customized according to application Can arrange in solution to form polymeric micelles |
Widely used for drug delivery and medical imaging Application and characteristics differ according to molecular weight ((Moghimi and Hunter, 2000) |
| Polyplexes: | A combination of a cationic polymer and nucleic acid therapeutics PEI: A cationic polymer, accused of high toxicity Protamine: A natural polypeptide; composed of cationic arginine units Safer than PEI but less efficient FDA approved |
Used as non-viral vectors for gene delivery (Tros de Ilarduya et al., 2010) |
| Chitosan | A natural hydrophilic cationic polysacccahride FDA approved Biocompatible Biodegradable Derived from crustacean shells |
Used extensively for drug delivery Chitosan nanoparticles are positively charged and mucoadhesive and achieve sustained drug release ((Mohammed et al., 2017) |
| SF | Natural biopolymer Biodegradable Biocompatible Minor immunogenicity |
Nanoparticles can be synthesized from this polymer by various methods for treatment of cancer and other diseases (Gianak et al., 2018) |
| Albumin | Natural biopolymer Hydrophilic Mostly suitable for hydrophilic drugs |
Used extensively in drug delivery and medical imaging; there are many marketed formulations for treatment of cancer, diabetes, multiple sclerosis and other conditions (An and Zhang, 2017) |
| Gelatin | Natural biopolymer Hydrophilic Mostly suitable for hydrophilic drugs |
Used for drug and gene delivery for conditions such as; cancer, tuberculosis and human immunodeficiency viral infection (Yasmin et al., 2016) |
| Dextran | Natural biopolymer Hydrophilic Mostly suitable for hydrophilic drugs |
Often used with functionalization for specific targeting, for example, the CNS or liver cells (Foerster et al., 2016; Ibegbu, 2015; Liu et al., 2018) |
| PLA-PCL-PGA | Forms polymeric micelles Biodegradable Synthetic PLA is hydrophilic PCL is Hydrophobic PGA is Hydrophilic |
PGA, PLA and PCL and their copolymers are the most commonly used materials for nanoparticles synthesis for the purpose of drug delivery (Hans and Lowman, 2002) |
| PAMAM/PPI | Used as a dendritic platform PPI is the first-discovered dendrimer |
Used to incorporate hydrophobic drugs in particular, as they improve their solubility and control their release (Huang and Wu, 2018) |
| PHPMA | A non-biodegradable synthetic polymer | Synthesis of new drug delivery systems with tailored characteristics (Huang and Wu, 2018) |
| PACA | Synthesized by anionic polymerization Biodegradable Biocompatible FDA approved |
Used alone or with a copolymer for the purpose of drug delivery for cancer or other diseases. Widely used for delivery of different therapeutic agents in different forms of nanocarriers including: nanocapsules, nanospheres, long circulating nanoparticles and nanoparticles conjugated with targeting moieties (Yordanov, 2012) |
PLGA: polylactic co-glycolic acid; PEG: polyethylene glycol; PEO-PPO-PEO: polyethylene oxide-polypropylene oxide-polyethylene oxide; PEI: polyethyleneimine; SF: silk fibroin; PLA-PCL-PGA: polylactic acid-polycaprolactone-polyglycolic acid; PAMAM: polyamidoamine; PPI: polypropyleneimine; PHPMA: polyhydroxylpropylmethacrylamide; PACA: polyalkylcyanoacrylates.