Section 3 Applications

**73**

**Chapter 5**

**Abstract**

Applications

*and Oscar M. Suarez*

Biodegradable Chitosan Matrix

Titanium Dioxide for Biocidal

Access to drinkable water is increasingly difficult in developing nations. According to the World Health Organization, more than 1.2 billion people lack access to this resource. The scientific community has risen to the challenge by developing innovating methods to purify water. In this context, a chitosan/titanium dioxide biocomposite represents an appealing, economically viable solution to remove oils, heavy metals, and pathogen colonies from contaminated waters. The present chapter reports the study of a chitosan film matrix impregnated with nanoparticles, which was capable of expressing antibacterial properties when exposed to UV light. Several techniques allowed characterizing the biocomposite uniformity, corroborating the crystal structure and assessing the bonding type of this biocomposite mixture. Antibacterial tests with *Escherichia coli* (Gram-negative) and *Staphylococcus aureus* (Gram-positive) were completed via growth curve analysis and the Kirby-Bauer technique. The results of this encompassing study revealed that bacterial growth was reduced by more than 50%. Optical microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction helped to characterize this biocomposite film. This chapter discusses how a novel and biodegradable film represents a better antibacterial material that is able to eliminate pathogens cost-effectively.

Composite Reinforced with

*Johnny López Calero, Zuleika Oquendo Berríos*

**Keywords:** chitosan, titanium dioxide, anatase, *Escherichia coli*,

The widespread use of antibiotics has promoted the dissemination of multidrug

resistance (MDR) genes in bacteria, whereas nanoparticles (NPs) have proven to be effective when dealing with this bacteria type [1]. Superbugs (i.e., bacteria which are resistant to nearly all antibiotics) have evolved due to the abuse, misuse, and negligence of antibiotics. They are capable of transferring their resistance by mechanisms as plasmid [2], transposon [3], and integrons [4]. This means that just one superbug can render an infection nearly untreatable. Antibiotics target mainly three areas inside bacteria: the cell wall, the translational machinery, and the DNA replication system. Superbugs can develop genes capable of resisting the effect of

*Staphylococcus aureus*, composite, biocide

**1. Introduction**
