**5. Conclusions**

Increased resistance to antibiotics has a direct impact on humanity and is one of the most important public health problems worldwide. Especially in the respiratory tract (lower and upper), which involves pharyngotonsillitis, pneumonia and infections by endotracheal tube, new therapeutic possibilities are needed. APDT has been shown to be highly effective against the microorganisms that cause these diseases and several protocols with different photosensitizers and illumination devices have been developed to make aPDT a great therapeutic option. New molecules and nanotechnology have been developed to improve aPDT and break down barriers to clinical applications.

*Antimicrobial Photodynamic Therapy of the Respiratory Tract: From the Proof of Principles… DOI: http://dx.doi.org/10.5772/intechopen.95602*
