## 6 Biofilms and Healthcare-Associated Infections
### Chronic Wounds  
Forming biofilms is a critical characteristic of chronic wounds, playing a substantial role in their persistence and negatively impacting healing outcomes [205]. In contrast to acute wounds, chronic wounds demonstrate an increased vulnerability to biofilm formation, with research indicating that biofilms are found in around 60% of chronic wounds [206]. The immune system typically effectively manages infections in acute wounds, promoting routine wound healing. Chronic wounds exhibit an imbalanced immune environment that facilitates the formation and proliferation of biofilms [205].  
The EPS shield facilitates microbial persistence, sustaining colonization and resulting in chronic inflammation that interferes with wound-healing [207]. This persistent inflammatory condition creates a self-perpetuating cycle in which the growth of biofilms worsens immune dysfunction, thereby prolonging or preventing the healing of wounds [205]. Confronting the issue of biofilms in chronic wounds is crucial for enhancing treatment approaches and facilitating efficient wound care.  
The intricacy of addressing biofilms is amplified in chronic wounds that often include polymicrobial biofilms, consisting of many bacterial and fungus species. These polymicrobial communities engage in synergistic interactions, increasing their collective resistance to medicines and complicating treatment approaches [208]. This enduring resistance hinders the successful elimination of biofilms, leading to chronic infections that extend inflammation and obstruct the restoration of normal tissue function. Addressing the complex resistance mechanisms of biofilms is essential for creating more effective treatment strategies in chronic wound care.  
Biofilms are essential in the development and persistence of various chronic wound types, including diabetic foot ulcers, venous leg ulcers, pressure ulcers, and surgical wound infections. Each wound type presents distinct pathological conditions that impact biofilm formation and stability [209; 210; 211; 212]. For instance, diabetic foot ulcers are associated with high glucose levels that promote bacterial growth and the formation of biofilms [213]. In the case of venous leg ulcers, chronic venous insufficiency creates an inflammatory and nutrient-rich environment, which also encourages biofilm development [214; 215]. Once biofilms are established, they pose significant challenges to treatment. The EPS matrix acts as a barrier, shielding the infection from phagocytosis by immune cells and impeding the diffusion of antibiotics, which diminishes the efficacy of standard therapeutic interventions [216].  
In chronic wound management, biosensors provide a revolutionary method for the real-time detection and monitoring of biofilms. These sensors are often integrated into wound dressings that treat and safeguard the wound while offering diagnostic functionalities. These biosensors provide early management by identifying particular biomarkers associated with wound infection. Frequently seen biomarkers include pH and uric acid, which serve as significant indications of illness advancement [217; 218]. Moreover, a wider array of indicators, including lactic acid, oxygenation levels, inflammatory mediators, bacterial metabolites, and the presence of bacteria, may be detected by wearable biosensors [218; 219]. These non-invasive tests enable doctors to make prompt and precise judgments, reducing the risk of biofilm-associated illnesses and facilitating expedited recovery. Integrating sophisticated detecting technologies into wound care and biosensors improves patient outcomes and clinical management efficiency.