Table 2.

Representative studies administering phototherapy via optical waveguides for infection treatment

Infection Model	Treatment	Results	Reference
Osteomyelitis induced by S. aureus in tibia of SD rats	In vivo: Percutaneous administration of 635 ± 10 nm laser (fluence of 75 J/cm2) at 250 mW/cm2 for 4 hours post-IP injection of ALA (300 mg/kg)	Significant inhibition of bacterial growth after 24 hours	[711]
		No significant difference after 48 hours compared to ALA treatment only
Human root canals infected with E. faecalis	Ex vivo: Methylene blue (25 μg/mL) incubation for 5 minutes followed by illumination with 665 nm light (fluence 222 J/cm2)	97% killing after 7 days of sample incubation relative to no treatment controls.	[714]
In vivo and clinical H. pylori infection	In vivo: Several 15-minute treatments of 31 to 46 kJ of 408 nm light to porcine stomachs	Clinical results revealed transient decrease in infection 8 hours after treatment according to UBT	[715]
	Clinical: 15, 30, 45, or 60-minute treatment time; UBT and bacterial counts were evaluated at time of enrollment, 5 days, and 5 weeks after treatment, respectively.	CFU reduction was highest and only significant in the antrum (97.7% killing)
		The highest reduction in microbe count was observed in the 30-minute treatment group
In vitro and clinical H. pylori infection	In vitro: 2 cm2 spot size of 405 nm light (4, 8, 16, and 32 J/cm2 fluence) for 5 minutes	In vitro: 32 J/cm2 energy density caused a 5-log reduction of bacterial viability 7 days post-treatment	[585]
	Clinical: 1 cm2 spot size of 405 nm light (40 J/cm2 fluence) for 4.5 minutes in the antrum	Clinical: CFUs/gram of tissue demonstrated significant (91%) bacterial kill relative to non-treated samples
Periodontitis induced by P. gingivalis in SD rats	6, 12, 24, 48 J of 630 nm light for 1, 2, 4, and 8 minutes with toluidine blue (0.01, 0.1, and 1 mg/ml) for bacterial kill measurements	No detectable bacteria in 1 mg/mL toluidine blue with light treatment group and significant reductions (at least one log10) in viable count of all other treatment groups.	[210]
	48 J of 630 nm light was administered for 8 min using toluidine blue (0.01, 0.1, and 1 mg/ml) for bone loss measurements	Significant differences in reduction in bone loss in 0.1 and 1 mg/mL toluidine groups using 48 J of light
Clinical COVID-19 pulmonary infection	Blue and/or red light administered via endobronchial or pulmonary arterial routes proposed for antiviral, antibacterial, anti-inflammatory, and vasculoprotective effects	Proposed study design	[311]
Intubated patients with COVID-19 pulmonary infection and/or acute respiratory distress syndrome	Direct trachea-bronchial UVC irradiation (2.0-2.5 mW) for 6 minutes every 4 hours for 24 hours	Proposed study design	[561]

S. aureus: Staphylococcus aureus; SD: Sprague-Dawley; IP: intraperitoneal; ALA: 5-Aminolevulinic acid hydrochloride; E. faecalis: Enterococcus faecalis; InGaN: indium gallium nitride; UBT: urea breath test; CFU: colony forming unit; P. gingivalis: Porphyromonas gingivalis