Unilateral Basal Cell Carcinomas: An Unusual Entity Treated with Photodynamic Therapy

On-demand and tunable dual wavelength release of antibody using light-responsive hydrogels

There has been an increased interest in the use of protein therapeutics, especially antibodies, for the treatment of a variety of diseases due to their high specificity to tissues and biological pathways of interest. However, the use of antibodies can be hindered by physical aggregation, degradation, and diffusion when injected in vivo leading to the need for antibody-releasing depots for the controlled and localized delivery within tissues of interest. Here, we investigated photolabile hydrogel chemistries for creating on-demand and tunable antibody release profiles. Innovative, scalable synthetic procedures were established and applied for fabricating hydrogels with nitrobenzyl (NB) and coumarin (CMR) photolabile crosslinks that responded to clinically relevant doses of long-wavelength UV and short-wavelength visible light. This synthetic procedure includes a route to make a CMR linker possessing two functional handles at the same ring position with water-stable bonds. The photocleavage properties of NB and CMR crosslinked hydrogels were characterized, as well as their potential for translational studies by degradation through pig skin, a good human skin mimic. The mechanism of hydrogel degradation, bulk versus surface eroding, was determined to be dependent on the wavelength of light utilized and the molar absorptivity of the different photolabile linkers, providing a facile means for altering protein release upon hydrogel degradation. Further, the encapsulation and on-demand release of a model monoclonal antibody was demonstrated, highlighting the ability to control antibody release from these hydrogels through the application of light while retaining its bioactivity. In particular, the newly designed CMR hydrogels undergo surface erosion-based protein release using visible light, which is more commonly used clinically. Overall, this work establishes scalable syntheses and relevant pairings of formulation-irradiation conditions for designing on-demand and light-responsive material systems that provide controlled, tunable release of bioactive proteins toward addressing barriers to preclinical translation of light-based materials and ultimately improving therapeutic regimens.

Blue light versus red light for photodynamic therapy of basal cell carcinoma in patients with Gorlin syndrome: A bilaterally controlled comparison study

BACKGROUND

Photodynamic therapy (PDT) is a non-scarring alternative for treating basal cell carcinoma (BCC) in patients with Basal Cell Nevus Syndrome (BCNS), also known as Gorlin syndrome. In Europe, red light (635 nm) is the predominant source for PDT, whereas in the United States blue light (400 nm) is more widely available. The objective of this study was to conduct a head-to-head comparison of blue light and red light PDT in the same BCNS patients.

METHODS

In a pilot study of three patients with 141 BCC lesions, 5-aminolevulinate (20% solution) was applied to all tumors. After 4 h, half of the tumors were illuminated with blue light and the remainder with red light. To ensure safety while treating this many tumors simultaneously, light doses were escalated gradually. Six treatments were administered in three biweekly sessions over 4 months, with a final evaluation at 6 months. Tumor status was documented with high-resolution photographs. Persistent lesions were biopsied at 6 months.

RESULTS

Clearance rates after blue light (98%) were slightly better than after red light (93%), with blue light shown to be statistically non-inferior to red light. Eight suspicious lesions were biopsied, 5 after red light (5/5 were BCC) and 3 after blue light (1 was BCC). Blue light PDT was reportedly less painful.

CONCLUSION

Blue light and red light PDT appear to be equally safe and perhaps equally effective for treating BCC tumors in BCNS patients. Further studies to evaluate long-term clearance after blue light PDT are needed.

Treatment of Gorlin syndrome (nevoid basal cell carcinoma syndrome) with methylaminolevulinate photodynamic therapy in seven patients, including two children: interest of tumescent anesthesia for pain control in children

OBJECTIVE

To report our experience of methylaminolevulinate photodynamic therapy (MAL-PDT) in the treatment of multiple basal cell carcinoma (BCC) in adults and children with Gorlin syndrome (GS).

DESIGN

Report of cases.

SETTING

University of Montpellier, Department of Dermatology.

PATIENTS

Seven Gorlin patients (41 superficial or nodular carcinomas), including two children.

INTERVENTIONS

Prior superficial curettage for superficial BBCs or debulking for nodular BCCs was systematically performed. Methylaminolevulinic acid was applied topically to lesions 3 h before illumination with 635 nm red light for 10 min (37 J/cm(2)). To prevent treatment discomfort, analgesics and/or cooling by sprayed water were most often provided, and occasionally 1% lidocaine local anesthesia. A ropivacaine-lidocaine tumescent anesthesia was performed on the youngest patient.

MAIN OUTCOME MEASURES

The initial response rate; tolerance, particularly in children; cosmetic outcome.

RESULTS

Overall clearance in patients was 60% after one session of MAL-PDT and 78% after three sessions. Resolution of the lesions was accompanied by an excellent cosmetic outcome in all patients. Treatments were well tolerated in adults with moderate pain sensation during illumination. In a child, tumescent anesthesia assured excellent tolerance in all treatment stages.

CONCLUSION

We add our experience to previous articles that consider PDT as an interesting option in the treatment of GS. To our knowledge, this study is the first report of MAL-PDT in GS children using tumescent anesthesia. Specific guidelines for adult and pediatric patients remain to be established.