Ultraviolet light and photodynamic therapy induce apoptosis in nasal polyps

[Difficult-to-treat chronic rhinosinusitis-when the standard treatment is not effective and biologics are not available]

BACKGROUND

In recent years, significant improvements have been made in the treatment options for uncontrolled chronic rhinosinusitis (CRS) refractory to standard medical and surgical therapy. This is the result of a better understanding of the pathophysiology and the resulting development of biologicals for CRS with nasal polyps (CRSwNP). However, biologics are not (yet) available for all patients in Europe.

OBJECTIVE

Based on the session "Difficult-to-treat CRS, when biologics are not available" at the 29th Congress of the European Rhinologic Society (ERS) 2023 in Sofia, Bulgaria, the treatment options for uncontrolled CRS with the exclusion of biologics will be discussed.

MATERIALS AND METHODS

The content of the presentations "Is there a place for antibiotics?" "Indications for revision surgery," "Novel systemic treatment options," "Novel local treatment options," and "Phototherapy for nasal polyps" are outlined and supported by a review of the literature.

RESULTS

Various treatment options are available for managing uncontrolled CRS, even if biologic treatments are unavailable. Treatment options for type‑2 (T2) CRS include steroid rinses, repeated short-term oral steroids, steroid-eluting stents, and extended sinus surgery. In the case of nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD), acetylsalicylic acid (ASA) desensitization can be considered. Non-T2 endotypes or CRS without nasal polyps (CRSsNP) may benefit from several weeks of macrolides and xylitol rinses.

CONCLUSION

To accurately assess the efficacy of second-line therapies for treatment of difficult-to-treat CRS within an endotype-specific framework, additional controlled clinical trials are needed that take into account the heterogeneity of CRS endotypes.

A Carbon Nanodot Based Near-Infrared Photosensitizer with a Protein-Ruthenium Shell for Low-Power Photodynamic Applications

Near-infrared (NIR) light-activated photosensitization represents an encouraging therapeutic method in photodynamic therapy, especially for deep tissue penetration. In this context, two-photon activation, i.e., utilization of photons with relatively low energy but high photon flux for populating a virtual intermediate state leading to an excited state, is attractive. This concept would be highly advantageous in photodynamic therapy due to its minimal side effects. Herein, we propose that the combination of plasma protein serum albumin (HSA) containing several Ru complexes and NIR two-photon excitable carbon nanodots (Cdots), termed HSA-Ru-Cdots, provides several attractive features for enhancing singlet oxygen formation within the mitochondria of cancer cells stimulated by two-photon excitation in the NIR region. HSA-Ru-Cdot features biocompatibility, water solubility, and photostability as well as uptake into cancer cells with an endosomal release, which is an essential feature for subcellular targeting of mitochondria. The NIR two-photon excitation induced visible emission of the Cdots allows fluorescence resonance energy transfer (FRET) to excite the metal-to-ligand charge transfer of the Ru moiety, and fluorescence-lifetime imaging microscopy (FLIM) has been applied to demonstrate FRET within the cells. The NIR two-photon excitation is indirectly transferred to the Ru complexes, which leads to the production of singlet oxygen within the mitochondria of cancer cells. Consequently, we observe the destruction of filamentous mitochondrial structures into spheroid aggregates within various cancer cell lines. Cell death is induced by the long-wavelength NIR light irradiation at 810 nm with a low power density (7 mW/cm²), which could be attractive for phototherapy applications where deeper tissue penetration is crucial.

Open, prospective, multicenter study on postoperative intranasal phototherapy in nasal polyposis

BACKGROUND

The therapeutic effect of ultraviolet (UV) light is generally attributed to its immunosuppressive and immunomodulatory effects. Since chronic inflammation is the major factor in the development of nasal polyposis, we have previously used mixed ultraviolet-visible light (mUV-VIS, Rhinolight®) phototherapy for the treatment of nasal polyps.

AIMS

In the present open, multicenter study, our aim was to delineate whether mUV-VIS applied postoperatively in vivo together with intranasal steroid treatment could reduce the recurrence of nasal polyps.

METHODS

After functional endoscopic sinus surgery, one group of patients received mUV-VIS light together with standard intranasal steroid (mometason furoate 2 × 200 μg) application for a 12-week treatment period, whereas the other patient group obtained only intranasal steroid for the same duration. We recorded nasal endoscopy images and obtained demographical and clinical data, total nasal score (TNS), and nasal obstruction symptom evaluation (NOSE). We performed acoustic rhinometry and measured nasal inspiratory peak flow. Follow-up was 12 months.

RESULTS

We found that the recurrence of nasal polyps was significantly diminished, and based on video-endoscopic measurements, the size and grade of recurrent polyps were significantly smaller in the phototherapy-receiving group. Nasal obstruction values and NOSE were significantly better throughout the follow-up period in the mUV-VIS light-treated group than in the intranasal steroid monotreatment group.

CONCLUSIONS

Rhinophototherapy together with standard nasal steroid application may have a supportive role in the treatment of recurrent bilateral nasal polyps.

Photodynamic Therapy as a New Treatment for Chronic Rhinosinusitis - A Systematic Review

This review examines the latest evidence for photodynamic therapy (PDT) in treating chronic rhinosinusitis. MedLine, EMBASE and TRIP Database searches were conducted using the terms: "photodynamic" or "phototherapy" or "photo" and "sinusitis" or "rhinosinusitis," date range January 2000 to May 2020. A total of 192 records were initially identified, after duplicates and exclusions, 9 full papers and 3 abstracts were included. All study types including in-vitro, animal and human studies were evaluated. Whilst there is in-vitro evidence for the efficacy of PDT's bactericidal effect on drug resistant bacteria and biofilm viability, there are few clinical studies. PDT is a promising area of research, but larger, focused studies looking at the safety, delivery, efficacy, and patient selection are required before it can be considered a viable treatment for CRS.