Bacterial Nanocellulose Loaded with Bromelain: Assessment of Antimicrobial, Antioxidant and Physical-Chemical Properties

Janaína Artem Ataide,Angela Faustino Jozala,Márcia De Araújo Rebelo,Marli Gerenutti,Mahendra Rai,Marco Vinícius Chaud,Priscila Gava Mazzola,Nathália Mendes De Carvalho,Denise Grotto

doi:10.1038/s41598-017-18271-4

Abstract

Bacterial nanocellulose (BNC) has desirable properties for wound healing such as high purity, good shape retention, and high water binding capacity. Bromelain is a protease found in pineapple tissues and has been applied in several fields, it has anti-inflammatory and anticancer properties, promotes cell apoptosis, amongst others. In this work, a BNC based device for the controlled release of bromelain was developed. BNC were submersed in sterilized bromelain solution and incubated at 25 °C under 100 rpm for 24 h. Physical-chemical properties, protein concentration, antioxidant and antimicrobial activities were measured. Results demonstrate that BNC could improve bromelain antimicrobial activity 9 times. Those findings allow concluding that bromelain is a promising molecule to be incorporated into BNC’s. The BNC’s characteristics seem to represent a new promising delivery system of the loaded biomolecule, and protected from external actions.

Highlights

Bacterial nanocellulose (BNC) is an extracellular polysaccharide secreted mainly by Gluconacetobacter xylinus, among other bacteria of genera Gluconacetobacter, Agrobacterium Rhizobium, Pseudomonas, Sarcina, and Acetobacter[8,9,10]
Bromelain was incorporated in BNC membranes by immerging membranes in a bromelain solution
Bromelain solution was subjected to the same loading conditions, but without contact with the bacterial cellulose, and there was an enzymatic activity and protein decrease, which was considered to calculated bromelain loading into BNC membranes

Summary

Introduction

Bacterial nanocellulose (BNC) is an extracellular polysaccharide secreted mainly by Gluconacetobacter xylinus, among other bacteria of genera Gluconacetobacter, Agrobacterium Rhizobium, Pseudomonas, Sarcina, and Acetobacter[8,9,10]. BNC is produced in pure form, free of other polymers It can be molded into three-dimensional structures, able to retain high water amounts, mechanically resistant and biocompatible[11]. Proteolytic enzymes could be used as therapeutics adjuvants, due to their debridement and antimicrobial activities, facilitating tissue renewal process and accelerating ulcerated skin healing. Bromelain is a set of proteolytic enzymes found in pineapple (Ananas comosus) tissues such as stem, fruit and leaves, and has widespread applications, such as in the cosmetic and food industries, as well as in medicine[17,18,19]. Dutta and Bhattacharyya[23] reported that bromelain from pineapple crown leaves present nonspecific proteolytic, gelatinolytic, collagenase, fibrinolytic, acid and alkaline phosphatase, nuclease, peroxidase, with considerable anti-bacterial and anti-fungal activities. In a further study using specific cysteine proteases inhibitors, authors found that papain and bromelain antibacterial activity is not related to its proteolytic activity, and may be related to amidase and esterase activities[24]

Methods

Results

Conclusion