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Smart polymers for the controlled delivery of drugs - a concise overview.

Priya James H, John R, Alex A, Anoop KR - Acta Pharm Sin B (2014)

Bottom Line: Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications.The most significant weakness of all these external stimuli-sensitive polymers is slow response time.In this review, we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules, and we highlight various applications in the field of advanced drug delivery.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutics, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham University, AIMS Healthcare Campus, Kochi, Kerala 682041, India.

ABSTRACT
Smart polymers have enormous potential in various applications. In particular, smart polymeric drug delivery systems have been explored as "intelligent" delivery systems able to release, at the appropriate time and site of action, entrapped drugs in response to specific physiological triggers. These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties. The responses vary widely from swelling/contraction to disintegration. Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications. The most fascinating features of the smart polymers arise from their versatility and tunable sensitivity. The most significant weakness of all these external stimuli-sensitive polymers is slow response time. The versatility of polymer sources and their combinatorial synthesis make it possible to tune polymer sensitivity to a given stimulus within a narrow range. Development of smart polymer systems may lead to more accurate and programmable drug delivery. In this review, we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules, and we highlight various applications in the field of advanced drug delivery.

No MeSH data available.


Related in: MedlinePlus

Various stimuli responsible for controlling drug release from smart polymeric drug delivery systems.
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f0005: Various stimuli responsible for controlling drug release from smart polymeric drug delivery systems.

Mentions: A stimuli-sensitive or smart polymer undergoes an abrupt change in its physical properties in response to a small environmental stimulus. These polymers are also called as intelligent polymers because small changes occurs in response to an external trigger until a critical point is reached, and they have the ability to return to their original shape after trigger is removed1–3. The exclusivity of these polymers lies in their nonlinear response triggered by a very small stimulus and which produces a noticeable macroscopic alterations in their structure. Fig. 1 depicts various stimuli responsible for controlling drug release from smart polymeric drug delivery systems. These transitions are reversible and include changes in physical state, shape and solubility, solvent interactions, hydrophilic and lipophilic balances and conductivity. The driving forces behind these transitions include neutralisation of charged groups by the addition of oppositely charged polymers or by pH shift, and change in the hydrophilic/lipophilic balance or changes in hydrogen bonding due to increase or decrease in temperature. The major benefits of smart polymer-based drug delivery systems includes reduced dosing frequency, ease of preparation, maintenance of desired therapeutic concentration with single dose, prolonged release of incorporated drug, reduced side effects and improved stability4–6.


Smart polymers for the controlled delivery of drugs - a concise overview.

Priya James H, John R, Alex A, Anoop KR - Acta Pharm Sin B (2014)

Various stimuli responsible for controlling drug release from smart polymeric drug delivery systems.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590297&req=5

f0005: Various stimuli responsible for controlling drug release from smart polymeric drug delivery systems.
Mentions: A stimuli-sensitive or smart polymer undergoes an abrupt change in its physical properties in response to a small environmental stimulus. These polymers are also called as intelligent polymers because small changes occurs in response to an external trigger until a critical point is reached, and they have the ability to return to their original shape after trigger is removed1–3. The exclusivity of these polymers lies in their nonlinear response triggered by a very small stimulus and which produces a noticeable macroscopic alterations in their structure. Fig. 1 depicts various stimuli responsible for controlling drug release from smart polymeric drug delivery systems. These transitions are reversible and include changes in physical state, shape and solubility, solvent interactions, hydrophilic and lipophilic balances and conductivity. The driving forces behind these transitions include neutralisation of charged groups by the addition of oppositely charged polymers or by pH shift, and change in the hydrophilic/lipophilic balance or changes in hydrogen bonding due to increase or decrease in temperature. The major benefits of smart polymer-based drug delivery systems includes reduced dosing frequency, ease of preparation, maintenance of desired therapeutic concentration with single dose, prolonged release of incorporated drug, reduced side effects and improved stability4–6.

Bottom Line: Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications.The most significant weakness of all these external stimuli-sensitive polymers is slow response time.In this review, we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules, and we highlight various applications in the field of advanced drug delivery.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutics, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham University, AIMS Healthcare Campus, Kochi, Kerala 682041, India.

ABSTRACT
Smart polymers have enormous potential in various applications. In particular, smart polymeric drug delivery systems have been explored as "intelligent" delivery systems able to release, at the appropriate time and site of action, entrapped drugs in response to specific physiological triggers. These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties. The responses vary widely from swelling/contraction to disintegration. Synthesis of new polymers and crosslinkers with greater biocompatibility and better biodegradability would increase and enhance current applications. The most fascinating features of the smart polymers arise from their versatility and tunable sensitivity. The most significant weakness of all these external stimuli-sensitive polymers is slow response time. The versatility of polymer sources and their combinatorial synthesis make it possible to tune polymer sensitivity to a given stimulus within a narrow range. Development of smart polymer systems may lead to more accurate and programmable drug delivery. In this review, we discuss various mechanisms by which polymer systems are assembled in situ to form implanted devices for sustained release of therapeutic macromolecules, and we highlight various applications in the field of advanced drug delivery.

No MeSH data available.


Related in: MedlinePlus