BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Optimizing Photobiomodulation For Smooth Muscle Differentiation of Adipose-Derived Stem Cells Using Retinoic Acid and TGFβ in a Two-Dimensi onal Model DTSTART;VALUE=DATE-TIME:20260325T144000Z DTEND;VALUE=DATE-TIME:20260325T150000Z DTSTAMP;VALUE=DATE-TIME:20260426T060656Z UID:indico-contribution-803-10346@events.saip.org.za DESCRIPTION:Speakers: Christevie Mbuyu (Laser Research Centre)\nPhotobiomo dulation (PBM) refers to the application of low-level light at specific wa velengths delivered either continuously or in pulses with low and constant energy densities in order to modulate cellular activity. This study inves tigated the influence of PBM at 525 nm (green)\, 825 nm (near-infrared\; N IR) and a combination wavelength of both on adipose-derived stem cell (ADS C) using assays which assess cellular parameters such as proliferation\, v iability\, mitochondrial function\, extracellular matrix (ECM) production\ , migration and differentiation towards a smooth muscle cell (SMC) in th e presence of growth factors like retinoic acid (RA) and transforming grow th factor-β (TGF-β). ADSCs were exposed to fluences of 5 J/cm² and 10 J /cm² and assessed using metabolic (ATP)\, cytotoxicity (LDH)\, Giemsa for morphology\; mitochondrial membrane potential (MMP)\, collagen quantifica tion\, migration analysis and immunofluorescence staining of stemness and SMC associated markers. Morphological analysis demonstrated that ADSCs ini tially maintained a typical spindle-shaped morphology across all experime ntal groups. However\, fluence-dependent PBM effects became evident over t ime. Cultures exposed to 5 J/cm² maintained higher cell density and proli feration\, whereas 10 J/cm² groups showed sparser cultures and reduced gr owth\, consistent with the biphasic Arndt-Schulz response. ATP analysis su pported this trend with lower fluence groups demonstrating enhanced metabo lic activity by day 7\, while higher fluence groups showed reduced prolife ration. LDH levels remained low across all PBM-treated groups\, confirming the absence of cytotoxic effects. Mitochondrial analysis indicated a gene rally stable MMP values during early stages with increased levels at later stages suggesting mitochondrial adaptation during differentiation. Collag en production showed an early increase followed by a decline at later time points\, suggestive of ECM remodelling during cellular maturation. Migrat ion analysis revealed differences in cell motility between treatment group s\, indicating functional variations associated with PBM exposure. Immunof luorescence confirmed the progressive expression of smooth muscle associat ed markers including smooth muscle α actin\, desmin\, calponin and SMMHC during the experimental period. Collectively\, these findings demonstrate that PBM modulates ADSC behaviour in a fluence-dependent fashion and may s upport smooth muscle lineage development under inductive culture condition s further highlighting the potential role of PBM in regenerative medicine applications.\n\nhttps://events.saip.org.za/event/272/contributions/10346/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10346/ END:VEVENT BEGIN:VEVENT SUMMARY:Parameter study and optimization of real-time single-particle trac king DTSTART;VALUE=DATE-TIME:20260325T142000Z DTEND;VALUE=DATE-TIME:20260325T144000Z DTSTAMP;VALUE=DATE-TIME:20260426T060656Z UID:indico-contribution-803-10321@events.saip.org.za DESCRIPTION:Speakers: Salomon van Niekerk (University of Pretoria)\nThe re al-time tracking of single particles is a vastly under-developed experimen tal technique but it offers great potential in understanding molecular dyn amics. A suitable tracking system comprises three key components\, viz.\, a position sensor\, a control system\, and an output actuator. The positio n sensor enables accurate prediction of the particle location. For this co mponent\, various tracking methods often employ an estimator of which the scanning pattern is a crucial part. A laser beam is generally scanned in a fixed pattern whilst the photons emitted by the tracked particles are cap tured and the corresponding photon counts and position coordinates are use d to predict the particle location. This process is repeated until some fo rm of termination condition is met. The choice of fixed pattern plays a si gnificant role in the accuracy of the estimator and hence the tracking cap abilities of the set-up. In this presentation\, we will show how different patterns and detection strategies can be employed in conjunction with acc urate two-dimensional single-particle tracking (SPT) simulations of emitti ng and non-emitting particles to identify an optimal combination. Fluoresc ence and interferometric scattering (iSCAT) are simulated to represent emi tting and non-emitting particles respectively. The performance of each con figuration is evaluated using some statistical metrics (e.g.\, average tra cking error).\n\nhttps://events.saip.org.za/event/272/contributions/10321/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10321/ END:VEVENT BEGIN:VEVENT SUMMARY:The artificial optical microscope. DTSTART;VALUE=DATE-TIME:20260325T140000Z DTEND;VALUE=DATE-TIME:20260325T142000Z DTSTAMP;VALUE=DATE-TIME:20260426T060656Z UID:indico-contribution-803-10340@events.saip.org.za DESCRIPTION:Speakers: Alberto Diaspro (Department of Physics - University of Genoa)\nMultimodal optical microscopy has recently converged with artif icial intelligence (AI) to the computational prediction of fluorescence‑ based molecular\ncontrast from label‑free measurements. Fluorescence pla ys a crucial role in linking microscopy and spectroscopy at molecular leve l\, enabling image formation from the cellular to the molecular detail. A challenging development in this field is the coupling of fluorescence with label-free polarization and phase optical methods. We will discuss how t his convergence\, together with modern generative\nmodeling for in‑silic o labeling\, is turning the optical microscope into an intelligent Instrum ent that we name artificial microscope.\n\nhttps://events.saip.org.za/even t/272/contributions/10340/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10340/ END:VEVENT BEGIN:VEVENT SUMMARY:The efficacy of PAM fluorometry as a tool to quantify heat stress in wheat DTSTART;VALUE=DATE-TIME:20260325T130000Z DTEND;VALUE=DATE-TIME:20260325T132000Z DTSTAMP;VALUE=DATE-TIME:20260426T060656Z UID:indico-contribution-803-10320@events.saip.org.za DESCRIPTION:Speakers: Sarah Burnett (Univeristy of Pretoria)\nFluorescence (spontaneous emission) is a highly sensitive probe for a multitude of mol ecular processes during the light-dependent steps of photosynthesis in num erous organisms. In living organisms\, the fluorescence signal is dwarfed by reflection and scattering\; however\, the signal-to-noise ratio can be significantly enhanced by gating the fluorescence to sub-msshort excitati on pulses through a non-invasive technique known as pulse-amplitude-modula ted (PAM) fluorometry. Wheat is an economically important crop that is sus ceptible to heat stress and consequent yield reduction at temperatures abo ve 30°C. However\, the changes to molecular processes that cause the decr ease in yield have not been well reported. In this study\, PAM fluorometr y was used to investigate the effects of high temperatures on the energy t ransfer pathways during the light-dependent steps of photosynthesis. The q uantum efficiency of energy conversion from light to chemical energy was n ot significantly altered at 30°C but was reduced by 10.7% at 35°C. We sh ow that the biological changes due to the heat shock response to heat stre ss can be measured at a time resolution of 30 seconds. PAM fluorometry\, and thus fluorescence\, is able to provide information about the effects o f heat stress on electron transport during light-dependent photosynthesis. This opens many possible directions of study\, such as investigating the effects of different types of stress on photosynthesis or further modellin g the photosynthetic energy-transfer pathways under heat stress.\n\nhttps: //events.saip.org.za/event/272/contributions/10320/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10320/ END:VEVENT BEGIN:VEVENT SUMMARY:Laser-Based Photobiomodulation Enhances Beta Cell Differentiation and Functional Insulin Production in Immortalised Adipose-Derived Stem Cel ls DTSTART;VALUE=DATE-TIME:20260325T134000Z DTEND;VALUE=DATE-TIME:20260325T140000Z DTSTAMP;VALUE=DATE-TIME:20260426T060656Z UID:indico-contribution-803-10316@events.saip.org.za DESCRIPTION:Speakers: Olukemi Daramola (University of Johannesburg)\nThe g eneration of functional insulin-producing beta (β)-cells from stem cells represented a promising therapeutic strategy for diabetes mellitus. Photob iomodulation (PBM)\, a non-invasive light-based approach\, has emerged as a potential regulator of cellular metabolism\, proliferation\, and differe ntiation through mitochondrial stimulation and bioenergetic modulation. Th is study investigated the effect of laser-based PBM on the differentiation of immortalised adipose-derived stem cells (ADSCs) into functional β-cel ls under both two-dimensional (2D) and three-dimensional (3D) culture cond itions.\nImmortalised ADSCs were exposed to defined laser parameters to ev aluate their capacity to enhance β-cell lineage commitment and functional insulin production. Cellular health\, viability\, and metabolic activity were assessed using multiple complementary assays. Intracellular adenosine triphosphate (ATP) quantification determined mitochondrial bioenergetic a ctivity\, while lactate dehydrogenase (LDH) release was measured to evalua te cytotoxicity and membrane integrity. Morphological changes associated w ith differentiation were examined using Giemsa staining\, and β-cell-spec ific insulin granule formation was confirmed using dithizone (DTZ) stainin g. Additionally\, Live/Dead assays were performed to assess overall cell v iability and survival within both 2D monolayer and 3D scaffold-based cultu re systems.\nIt was hypothesized that laser-based PBM enhanced mitochondri al activity\, improved cellular viability\, and promoted the generation of metabolically active\, insulin-producing β-cells\, with enhanced outcome s observed in 3D culture systems due to improved cell–cell and cell–ma trix interactions.\nThis study aimed to advance understanding of laser-bas ed PBM mechanisms in stem cell differentiation and to support the developm ent of non-invasive strategies for β-cell engineering and regenerative di abetes therapies.\n\nhttps://events.saip.org.za/event/272/contributions/10 316/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10316/ END:VEVENT BEGIN:VEVENT SUMMARY:BALANCING CELL COMPATIBILITY AND ANTIMICROBIAL EFFECTS OF 470 NM I N AN INFECTED HYPERGLYCAEMIC WOUND CELL MODEL DTSTART;VALUE=DATE-TIME:20260325T132000Z DTEND;VALUE=DATE-TIME:20260325T134000Z DTSTAMP;VALUE=DATE-TIME:20260426T060656Z UID:indico-contribution-803-10312@events.saip.org.za DESCRIPTION:Speakers: Francis Obeng Brenya (University of Johannesburg)\nF .O. Brenya1 and N.N. Houreld1*\n1Laser Research Centre\, University of Joh annesburg\, Johannesburg\, South Africa \nE-mail: nhoureld@uj.ac.za*\nAnti microbial photobiomodulation (aPBM) with blue light (400-490 nm) is a prom ising non-invasive adjunct therapy for infected chronic diabetic foot ulce rs (DFUs). Still\, its fluence-dependent effects on human dermal fibroblas ts remain poorly defined. This study investigated the fluence-dependent re sponse of fibroblasts (BJ-5ta) cultured under three conditions: normal (N) \, normal wounded (NW)\, and hyperglycaemic wounded (HW)\, with or without bacterial infection. BJ-5ta fibroblasts (6 × 10⁵ cells/mL) were co-cu ltured with Staphylococcus aureus\, Streptococcus pyogenes\, or Pseudomona s aeruginosa (1.5×10³ CFU/mL) and irradiated with 470 nm blue laser ligh t (power output 800 mW\; power density 88 mW/cm²) at 5\, 10\, 30\, 55\, 1 00\, or 120 J/cm². After 24 hours\, fibroblast viability\, migration\, mo rphology\, and bacterial survival were evaluated. Low fluences (5-10 J/c m²) maintained fibroblast viability at ≥90% across all uninfected model s. In contrast\, higher fluences (30-120 J/cm²) caused a marked\, dose- dependent decrease in fibroblast viability\, with the lowest values observ ed at 120 J/cm² in both normal and hyperglycaemic wounded models. Infec tion with S. aureus\, S. pyogenes\, and P. aeruginosa increased cytotoxic ity\, with each species showing the greatest reduction in fibroblast viabi lity at ≥55 J/cm². Fibroblast migration in the uninfected normal woun ded model decreased progressively at fluences over 30 J/cm²\, dropping to 22-30% at 120 J/cm². In infected normal wounded models\, migration d eclined in a species-dependent manner\, with minimum values of 22-30% for S. aureus\, 37-48% for S. pyogenes\, and 21-27% for P. aeruginosa at 120  J/cm². CFU counts were significantly reduced at 5-10 J/cm² for all species. At 30-120 J/cm²\, S. aureus and P. aeruginosa were unaffected\ , whereas S. pyogenes exhibited a sustained\, significant decrease in bact erial load. These results suggest a potential therapeutic window at 5-30  J/cm²\, within which fibroblast function is largely preserved while ba cterial burden is reduced\, supporting dose-optimised application of 470  nm aPBM in vitro.\n\nhttps://events.saip.org.za/event/272/contributions /10312/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10312/ END:VEVENT END:VCALENDAR