Question

referring to the paper  "Recent insights on applications of pullulan in tissue engineering", authored by RS Singh, N Kaur, V Rana, and JF Kennedy. It was published in Carbohydrate Polymers, 2016, 153, 455-462.

Which are the physical traits of pullulan which recommend this polymer for tissue engineering ?

How injured tissues can be repaired with the help of artificially created polymeric scaffolds ?

Please mention few pullulan derivatives and explain why the derivatization was necessary for a particular type of application ?

Which are on your opinion the main challenges related to usage of pullulan in tissue engineering ?

Answer 1

1. The surface of pullulan polymer contains nine hydroxyl groups along with the pattern of α-(1 → 4) and  α-(1 → 6) linkages found to be uncommon characteristics for tissue engineering.

2. The 3D structure of artificially created polymeric scaffolds helps to revive the damaged tissues by repeating the architectural structure of normal tissues through collagen fibres from extracellular matrix (ECM).

3. In order to extend the applications of pullulan, it can be derivatized and tuned in such a way that to extend its application of carrier in drug delivery. Moreover, each derivative shows a distinct characteristics by modifying the chemical structure of pullulan backbone which works well in particular tissue damages.

Pullulan Derivatives	Application
Cholesterol bearing pullulan	hydrophobically modified polymer acts as a good carrier for hydrophobic molecules such as insulin and drug carrier for cancer
Pullulan acetate	The presence of formamide and pyridine helps for long circulation of blood and drug delivery for targeted cancer cell
Carboxymethyl pullulan	having anti-oxidant property, controlled drug delivery and metal retaining property
Pullulan succinylate	Microspheres of pullulan succinylate swells 20 times on entering intestinal fluid and stable in acidic environment.
Pullulan amine	target cancer cells in lung, kidney, brain, liver and ovary.

4. Multitasking pullulan based scaffolds possibly the current need in tissue engineering for natural healing of tissues in patients.