Enzymes’ action on materials: Recent trends

Enzyme-Embedded Degradation of Poly(ε-caprolactone) using Lipase-Derived from Probiotic Lactobacillus plantarum

Enzyme-embedded polymer degradation was reported to be an attractive alternative approach to the conventional surface pouring method for efficient degradation of polymers using fungal-derived enzyme Candida antarctica lipase B. Despite the enormous potential, this approach is still in its infancy. In the present study, a probiotic lipase obtained from Lactobacillus plantarum has been employed for the first time to study the enzyme-embedded polymer degradation approach using poly(ε-caprolactone) (PCL) as the semicrystalline polymer candidate. PCL films embedded with 2 to 8 wt % lipase are studied under static conditions for their enzymatic degradation up to 8 days of incubation. Thermogravimetric analyses (TGA) have shown a clear trend in decreasing thermal stability of the polymer with increasing lipase content and number of incubation days. Differential thermal analyses have revealed that the percentage crystallinity of the leftover PCL films increases with progress in enzymatic degradation because of the efficient action of lipase over the amorphous regions of the films. Thus, the higher lipase loading in the PCL matrix and more number of incubation days have resulted in higher percentage crystallinity in the leftover PCL films, which has further been corroborated by X-ray diffraction analyses. In a similar line, higher percentage mass loss of the PCL films has been observed with increased enzyme loading and number of incubation days. Field emission scanning electron microscopy (FE-SEM) has been employed to follow the surface and cross-sectional morphologies of the polymer films, which has revealed micron-scale pores on the surface as well as a bulk polymer matrix with progress in enzymatic polymer degradation. Additionally, FE-SEM studies have revealed the efficient enzyme-catalyzed hydrolysis of the polymer matrix in a three-dimensional fashion, which is unique to this approach. In addition to the first-time utility of a probiotic lipase for the embedded polymer degradation approach, the present work provides insight into the PCL degradation under static and ambient temperature conditions with no replenishment of enzymes.

In vitro hemocompatability evaluation of gold nanoparticles capped with Lactobacillus plantarum derived lipase1

BACKGROUND

Gold nanoparticles (GNPs) are key diagnostic and therapeutic agents in biomedical sciences. Several studies have been carried out in different therapeutic areas such as in cancer treatment, antibacterial topical agents, imaging agents etc. There is a necessity to evaluate the gold nanoparticles cytotoxicity at all fronts. Since blood is the first point of contact in any therapy, it is required to have a thorough in vitro investigation of gold nanoparticles to avoid any adverse effects.

OBJECTIVE

The objective of the current study is to evaluate the effect of gold nanoparticles capped with lipase on blood clotting factors, platelets, coagulation time and blood clotting strength.

METHODS

Whole blood samples were drawn from healthy volunteers. Plasma and plasma with platelets were isolated from the blood and all the samples were treated with lipase capped gold nanoparticles, except control. Plasma fibrinogen formed in the blood coagulation process after contacting with nanoparticles was quantitatively evaluated. In addition, platelet aggregation, blood clotting kinetics, strength of the blood clot and time were evaluated post nanoparticle treatment.

RESULTS

The work primarily explores the effect of GNPs on blood with changing concentrations of lipase capping. Plasma fibrinogen levels of plasma samples were found to be moderately elevated, however, there is no significant effect on blood clotting kinetics, strength, and platelet aggregation. Also, the study showed that lipase capped GNPs did not result in aggregation upon interaction with plasma components and remained stable for 1 hour after incubation.

CONCLUSIONS

Our study revealed that lipase capped GNPs synthesized using NaBH4 approach were stable and hemocompatible. There is an increase in fibrinogen levels after the exposure to nanoparticles, an observation which is consistent with other studies. However, the functional consequences of such increase are unknown. The results of no significant platelet aggregation, change in blood clotting time, kinetics, and clot strength revealed the non-toxic effect of lipase capped GNPs towards blood components, which is essential for any in vivo applications.