Polycaprolactone (PCL) is a biodegradable polymer composed of hexanoate repeat units. It has several advantageous properties including being non-toxic, biodegradable in soil, and having broad miscibility. PCL is synthesized via ring-opening polymerization of the monomer ε-caprolactone. It undergoes degradation in two stages - non-enzymatic hydrolytic cleavage followed by intracellular degradation. PCL has various applications such as controlled drug delivery and tissue engineering scaffolds due to its biodegradability and permeability. It is commonly used to produce microspheres, microcapsules, and fibers for long-term drug release. Recent research

1. 1

2. 2
CONTENTS:
1. General description
2. Introduction
3. Synthesis
4. Biodegradation
5. Pharmaceutical applications
6. Other applications
7. Recent advancements
8. Advantages and disadvantages
9. References

3. 1. GENERAL DESCRIPTION:
Biodegradable polymer
Non-toxic
Biodegradable in soil
Broad miscibility
Mechanical compatibility with many polymers and good adhesion to a
broad spectrum of substrates.
IUPAC name: (1,7)-Polyoxepan-2-one
Systematic IUPAC name: Poly(hexano-6-lactone)
Other names: 2-Oxepanone homo polymer
6-Caprolactone polymer
Melting point: 60 °C (140 °F)
Density: 1.071 g/ml
Chemical formulae: (C6H10O2)n
Molecular weight: 3000-80,000 g/mol
3

4. 2. INTRODUCTION:
Polycaprolactone (PCL) is a polymer composed of hexanoate repeat units, included
in the class of aliphatic polyesters.
PCL has been thoroughly investigated for its peculiar mechanical properties,
miscibility with a large range of other polymers, and biodegradability.
The physical, thermal, and mechanical properties of PCL mainly depend upon its
molecular weight and degree of crystallinity.
PCL is strongly hydrophobic, semicrystalline, highly soluble at room temperature.
Easily processable due to the low melting temperature and exceptional blend
compatibility.
4

5. PCL has been extensively studied for the preparation of controlled drug delivery
systems.
Its permeability to a wide range of drugs enabled uniform drug distribution in the
matrix, assuring along-term release up to several months by a degradation
mechanism.
PCL has been largely used for the preparation of long-term implants and scaffolds .
PCL has also been certified as FDA approved (Food and Drug Administration,
USA) and CE registered mark (European Community)
5

6. 3. SYNTHESIS:
The first synthesis of PCL by thermal treatment of 𝜀-caprolactone was reported
by Van Natta and co-workers.
PCL is still mainly synthesized by ionic and metal catalyzed ring-opening
polymerization (ROP) of the cyclic monomer 𝜀 –caprolactone.
The radical ring opening polymerization (RROP) of 2-methylene-1,3-dioxepane
(MDO), using different conditions, and on the condensation of 6-hydroxycaproic
acid
6
Stannous octonoate

7. The poly condensation of 6-hydroxycaproic acid, this synthetic route is also
reported.
The most interesting approaches are based on the enzymatic synthesis, such as
those based on the use of lipase .
The use of Candida Antarctica Lipase B (CALB) immobilized on acrylic resin
slowly gives rise to PCL with an average degree of polymerization.
7

8. 4. BIODEGREDATION:
PCL is degraded by hydrolysis of its ester linkages in physiological conditions
(such as in the human body)
PCL undergoes a two-stage degradation process:
The non enzymatic hydrolytic cleavage of ester groups.
When the polymer is more highly crystalline and has a low molecular
weight (less than 3000) the polymer is shown to undergo intracellular
degradation.
Degradation is started by the hydrolysis of polymer chain 6-hydroxyhexanoic
acid to acetyl co enzyme A which goes further degradation in TCA.
8

9. 9

10. 5. PHARMACEUTICAL APPLICATIONS:
PCL is suitable for controlled drug delivery due to a high permeability to many
drugs
Biodegradation of PCL is slow in comparison to other polymers, so it is more
suitable for long-term delivery.
PCL also has the ability to form compatible blends with other polymers which
can affect the degradation kinetics.
10

11. 11
Several drug delivery vehicles composed of PCL, such as microspheres,
microcapsules, nano spheres and micro and nano fibers have been developed for
the controlled release of drugs or protein.

12. 6. OTHER APPLICATIONS:
PCL loaded with antibiotics may be used to treat infections of the respiratory
tract, like tuberculosis.
Investigations were carried out based upon phenotypic responses of human bone
marrow mesenchymal cells .
PCL/biomedical ceramic materials have been studied for possible osteo tissue
regeneration.
Action of PCL/graded insulin/beta-5 glycerophosphate concentrations on
osteochondral tissue formation.
Other general uses include: extrusion aid, die lubricant, mold release, pigment
and filler dispersion aid and polyester segments in urethanes and block polyesters.
12

13. 7. RECENT ADVANCEMENTS:
PCL attracted interest for the design of green materials/biomaterials
used for various applications.
PCL mechanical properties make it suitable for medical applications
complementary to tissue engineering, such as, for example, wound
dressing, contraceptive, and dentistry but also in non medical fields
such as environment, packaging and food.
13

14. 8. ADVANTAGES AND DISADVANTAGES:
14

15. 15
9. REFERENCES:
1. Bikiaris D N, Papageorgiou G Z, Achilias D S, Pavlidou E and Stergiou A.
"Miscibility and enzymatic degradation studies of poly(e-
caprolactone)/poly(propylene succinate) blends". European Polymer Journal,
Vol 43, 2007, pp. 2491–2503.
2. Johnson J, Niehaus A, Nichols S, Lee D, Koepsel J, Anderson D and Lannutti
J, "Electrospun PCL in vitro: a microstructural basis for mechanical property
changes". J. Biomater. Sci. Polymer Edn, Vol 20, 2009, pp. 467–481.

16. 16