Aaron Song Chuan Foo

Present day strategies for delivery of wireless photodynamic therapy (PDT) to deep-seated targets are limited by the inadequacy of irradiance and insufficient therapeutic depth. Here we report the design and preclinical validation of a flexible wireless upconversion nanoparticle (UCNP) implant (SIRIUS) that is capable of large field, high intensity illumination for PDT of deep-seated tumors. The implant achieves this by incorporating submicrometer core-shell-shell NaYF₄ UCNPs into its design, which significantly enhances upconversion efficiency and mitigates light loss from surface quenching. We demonstrate the efficacy of SIRIUS UCNP implant mediated PDT in preclinical breast cancer disease models. In our in vitro experiments, SIRIUS directed 5-Aminolevulinic Acid (5-ALA) based wireless PDT leads to significant reactive oxygen species (ROS) generation and tumor apoptosis in hormonal receptor+/HER2+ (MCF7) and triple-negative (MDA-MB-231) breast cancer cell lines. In our in vivo rodent model, SIRIUS-driven PDT is shown to be significant in regressing tumors when applied to orthotopically inoculated breast tumors. Following successful preclinical validation, we also describe a clinical prototype of UCNP breast implant with potential dual cosmetic and onco-therapeutic functions. SIRIUS is an upconversion breast implant for wireless PDT that fulfils all the design prerequisites necessary for seamless clinical translation.

Glioblastoma multiforme (GBM) is an aggressive brain tumor with poor prognosis and high mortality, with no curative treatment to date as limited trafficking across the blood–brain barrier (BBB) combined with tumor heterogeneity often leads to therapeutic failure. Although modern medicine poses a wide range of drugs that are otherwise efficacious in treating other tumors, they often do not achieve therapeutic concentrations in the brain, hence driving the need for more effective drug delivery strategies. Nanotechnology, an interdisciplinary field, has been gaining immense popularity in recent years for remarkable advancements such as nanoparticle (NP) drug carriers, which possess extraordinary versatility in modifying surface coatings to home in on target cells, including those beyond the BBB. In this review, we will be highlighting recent developments in biomimetic NPs in GBM therapy and how these allowed us to overcome the physiological and anatomical challenges that have long plagued GBM treatment.

Burrhole craniostomy is commonly performed for subdural hematoma (SDH) evacuation, but residual scalp depressions are often cosmetically suboptimal for patients. Osteoplug^TM, a bioresorbable polycaprolactone burrhole cover, was introduced by the National University Hospital, Singapore, in 2006 to cover these defects, allowing osseous integration and vascular ingrowth. However, the cosmetic and safety outcomes of Osteoplug^TM-C—the latest (2017) iteration, with a chamfered hole for subdural drains—remain unexplored. Data were collected from a single institution from April 2017 to March 2021. Patient-reported aesthetic outcomes (Aesthetic Numeric Analog (ANA)) and quality of life (EQ-5D-3L including Visual Analog Scale (VAS)) were assessed via telephone interviews. Clinical outcomes included SDH recurrence, postoperative infections, and drain complications. Osteoplug^TM-C patients had significantly higher satisfaction and quality of life compared to those without a burrhole cover (ANA: 9 [7, 9] vs. 7 [5, 8], p = 0.019; VAS: 85 [75, 90] vs. 70 [50, 80], p = 0.021), and the absence of a burrhole cover was associated with poorer aesthetic outcomes after multivariable adjustment (adjusted OR: 4.55, 95% CI: 1.09–22.68, p = 0.047). No significant differences in other clinical outcomes were observed between Osteoplug^TM-C, Osteoplug^TM, or no burrhole cover. Our pilot study supports Osteoplug^TM-C and its material polycaprolactone as suitable adjuncts to burrhole craniostomy, improving cosmetic outcomes while achieving comparable safety outcomes.

To assess the awareness and acceptability of colorectal cancer (CRC) screening in noncompliant Singaporeans and to determine if their barriers can be overcome by education. A questionnaire developed from thematic analysis of open-ended interviews with 72 subjects was administered to 580 residents in a local high-rise housing estate. Participants aware of CRC screening were assessed for barriers and acceptability of CRC screening. All participants were subsequently educated about CRC screening and reassessed for barriers and acceptance. Those keen for fecal occult blood testing (FOBT) were offered FOBT kits and followed up. CRC screening awareness was poor. Having no symptoms was the most common barrier. More barriers to FOBT than to colonoscopy were reduced with education. After education, acceptability toward FOBT increased but rejection rates rose even higher. FOBT is probably Singapore’s most acceptable screening modality. Education is limited by barriers, which need to be overcome by alternative measures.