Papers by Myla Santiago
Doxorubicin hydrochloride (DOX) is used in treating ovarian, lung, and breast cancers. Its use in... more Doxorubicin hydrochloride (DOX) is used in treating ovarian, lung, and breast cancers. Its use in cancer chemotherapy is limited due to short plasma circulation, long elimination half-life, and non-specific cytotoxicity that may affect the normal cells. Thus, we have designed a drug delivery system, using a naturally occurring anionic polymer that is used for drug delivery due to its inert nature, high degree of biocompatibility, low toxicity, inexpensive and mild gelation with divalent cations such as calcium in forming particles. In this research, calcium alginate was used to encapsulate doxorubicin and assessed its compatibility with calcium alginate as drug delivery system. pH compatibility of alginate particle formation were assessed relative to the affinity of DOX. Alginate efficiency to encapsulate DOX was also tested and characterized through morphological analysis of the particles with the use of phase contrast microscope and scanning electron microscope (SEM). Fourier tran...
Alginate is a non-toxic, biodegradable, and naturally occurring polysaccharide found in marine br... more Alginate is a non-toxic, biodegradable, and naturally occurring polysaccharide found in marine brown algae. It has a long list of use in numerous drug delivery systems due to its biodegradability and biocompatibility. The study aimed to encapsulate doxorubicin using alginate via ionotropic gelation method and assess the capacity of encapsulated drug to kill breast cancer cells through cell viability assay. Formulation of alginate-based particles was done through ionotropic gelation method. Preliminary test include encapsulation of solution with pH indicators to determine the biocompatibility of alginate to doxorubicin. The results showed compatibility of calciumalginate with basic and acidic solutions. Encapsulation of doxorubicin in calcium-alginate based particles exceeded 90% encapsulation efficiency. The encapsulated drug manifests a controlled release profile of 7% in PBS pH 7.4 at 37ï‚°C during the first hour. Delayed drug release is vital in drug delivery system. The capacity o...
Lung cancer is the leading cause of cancer deaths worldwide with non-small cell lung cancer (NSCL... more Lung cancer is the leading cause of cancer deaths worldwide with non-small cell lung cancer (NSCLC) as most prevalent and majority of cases are diagnosed at advanced stage. Mutations related to exon 20 (T790M) and 21 (L828R) are most prevalent in NSCLCs and determines response to EGFR-tyrosine kinase inhibitors (TKI) therapy. Two of the most frequently used methods in detecting EGFR mutations in both exons, namely high resolution melting analysis (HRM) and pyrosequencing were cross validated based on frequency and accuracy of mutation detected using genomic DNA of 174 formalin-fixed paraffin embedded (FFPE) tissue samples in CTMA laboratory Brussels, Belgium. HRM is a cheap-gel free method based on the formation of heteroduplexes between mutant and wild-type alleles that exhibits high sensitivity and specificity and detects mutant genes at levels of 2.5-10%2. While, pyrosequencing is an alternative method to Sanger sequencing, its quick, gel-free method can detect mutations in at le...
Journal of Oleo Science, 2019
Introduction Marine oomycetes are a group of fungal-like eukaryotes of the kingdom Straminipila 1... more Introduction Marine oomycetes are a group of fungal-like eukaryotes of the kingdom Straminipila 1. Members of this group are considered as initial colonizers of fallen senescent mangrove leaves 1 and are seen as a potentially good source of fatty acids e.g. polyunsaturated and monounsaturated that are of industrial and medical importance 2 4. Polyunsaturated fatty acids PUFAs are biological lipid derivatives which are essential in human metabolism and other biological activities 5. One application of PUFAs in the medical field is its cytotoxic and apoptotic activity against cancer
Doxorubicin hydrochloride (DOX) is used in treating ovarian, lung,
and breast cancers. Its use in... more Doxorubicin hydrochloride (DOX) is used in treating ovarian, lung,
and breast cancers. Its use in cancer chemotherapy is limited due to
short plasma circulation, long elimination half-life, and non-specific
cytotoxicity that may affect the normal cells. Thus, we have designed a
drug delivery system, using a naturally occurring anionic polymer that
is used for drug delivery due to its inert nature, high degree of
biocompatibility, low toxicity, inexpensive and mild gelation with
divalent cations such as calcium in forming particles. In this research,
calcium alginate was used to encapsulate doxorubicin and assessed its
compatibility with calcium alginate as drug delivery system. pH
compatibility of alginate particle formation were assessed relative to the affinity of DOX.
Alginate efficiency to encapsulate DOX was also tested and characterized through
morphological analysis of the particles with the use of phase contrast microscope and
scanning electron microscope (SEM). Fourier transform infrared spectrophotometer (FTIR)
was used to confirm if the DOX was able to encapsulate within the alginate particles. Results
showed that alginate encapsulation was compatible with DOX at neutral pH and
encapsulation efficiency was achieved at 99.30%±0.0045 for 10ppm of DOX and
95.16%±0.011 for the 1.25ppm of DOX. An observable DOX-alginate particles with size
average of 100-300μm using phase contrast microscope (40-60X magnification) and scanning
electron microscope (200-300X magnification). DOX release in phosphate buffered saline
(pH 7.2) confirmed that the DOX was successfully encapsulated based in FTIR data with
comparable differences in the functional groups of DOX, alginate, and DOX released from the particles.
Alginate is a non-toxic, biodegradable, and naturally occurring
polysaccharide found in marine br... more Alginate is a non-toxic, biodegradable, and naturally occurring
polysaccharide found in marine brown algae. It has a long list of use
in numerous drug delivery systems due to its biodegradability and
biocompatibility. The study aimed to encapsulate doxorubicin using
alginate via ionotropic gelation method and assess the capacity of
encapsulated drug to kill breast cancer cells through cell viability
assay. Formulation of alginate-based particles was done through
ionotropic gelation method. Preliminary test include encapsulation of
solution with pH indicators to determine the biocompatibility of
alginate to doxorubicin. The results showed compatibility of calciumalginate
with basic and acidic solutions. Encapsulation of doxorubicin in calcium-alginate
based particles exceeded 90% encapsulation efficiency. The encapsulated drug manifests
a controlled release profile of 7% in PBS pH 7.4 at 37ï‚°C during the first hour. Delayed drug
release is vital in drug delivery system. The capacity of the encapsulated doxorubicin against
free doxorubicin to kill tumor cells was determined by an in vitro cell culture using breast
cancer cells and tests its cell proliferative activity by MTT assay. Trypan Blue Assay showed
the cell density upon delivery of the encapsulated drug decreased as time progressed. While the MTT assay showed that the encapsulated drug can inhibit the breast cancer cells proliferation with a 12.85%, 77.75% and 96.45% inhibition during 20, 40, and 60 hours respectively (p0.050). In that note, encapsulation of doxorubicin in a calcium alginate based particles are proven to be effective in terms of drug delivery, breast cancer cells viability and in minimizing chemoresistance of cells.
Conference Presentations by Myla Santiago
Hypercholesterolemia, or high cholesterol levels, is a major factor influencing the development o... more Hypercholesterolemia, or high cholesterol levels, is a major factor influencing the development of cardiovascular diseases (CVD). Previous studies on several types of kefir, a fermented drink rich in probiotic bacteria, have proved its potential in decreasing blood cholesterol levels. This study aims to screen, characterize and purify bile salt hydrolase (BSH), an enzyme produced by lactic acid bacteria (LAB) isolated from cocowater kefir. LAB strains were isolated from cocowater kefir and screened for BSH activity in order to select strains with cholesterol-lowering properties. BSH activity was measured by determining the amount of taurine or glycine liberated from conjugated bile salts of LAB strains from cocowater kefir. Substrate specificity was determined based on the greater amount of amino acid conjugated bile salt produced by each LAB strains. Among the LAB strains tested, five representative strains with the highest BSH activity were further assayed for its ability to coprecipitate cholesterol with deconjugated bile in vitro. The quality of bile salt hydrolase produced was assessed via SDS-PAGE prior to purification.The genomic DNA of the most promising LAB isolate was extracted and subjected to sequence analysis for proper identification. These results suggest LAB isolated from Philippine coconut water kefir can be novel source of cheap, safe and efficient probiotics with cholesterol lowering properties in developing functional foods or supplements in treating cholesterol related diseases such as CVD. Keywords – bile salt hydrolase, cocowater kefir, lactic acid bacteria,
Bile salt hydrolase (BSH) is an enzyme produced by lactic acid bacteria that holds promise in low... more Bile salt hydrolase (BSH) is an enzyme produced by lactic acid bacteria that holds promise in lowering cholesterol levels, consequently decreasing the risk of cardiovascular diseases, with its presence having been correlated to hypocholesterolemic effects of food rich in probiotic bacteria, such as in kefir. In this study, lactic acid bacteria (LAB) isolates from cocowater kefir were screened for BSH activity, followed by the extraction and purification of the enzyme. The isolates were screened by observing the precipitation of deconjugated bile salts in a specific media. Purification was done via ammonium salt precipitation and size exclusion gel chromatography using Sephadex G-100. The crude and purified extracts were then assayed for protein content, using Bradford’s assay, and for BSH activity. Determination of BSH activity was done by measuring the amount of glycine liberated from the deconjugation of the bile salt glycocholic acid. Four isolates, preliminary identified as I002, I004, J006 and K001 upon isolation from cocowater kefir, were subjected to the purification process and the improvement of enzyme activity was analyzed. Additionally, genomic DNA extraction was performed on the four isolates for identification of the BSH-producing bacteria. The initial enzyme activities of the crude enzyme extracts from the isolates were found to be 1.33x10-4 U/mg, 1.28x10-4 U/mg, 1.25x10-4 U/mg and 1.13x10-4 U/mg, respectively. After salt precipitation, the enzyme activities increased to 4.35x10-4 U/mg, 5.41x10-4 U/mg, 4.25x10-4 U/mg and 5.20x10-4 U/mg, respectively. Finally, after gel chromatography, the eluates were assayed, and peak enzyme activities were determined to be at 7.23x10-4 U/mg from I002, 1.98x10-3 U/mg from I004, 3.55x10-4 U/mg from J006 and 2.50x10-4 U/mg from K001. From the results gathered, enzyme activity was observed to increase with every purification step for bacteria isolates I002 and I004, with the gel chromatography filtrates producing the highest enzyme activity per milligram of protein. The decrease in activity observed in isolates J006 and K001 could possibly be due to the elution conditions, thus requiring adjustments for the two isolates. Additionally, it was determined that bacteria isolate I004 expressed the highest enzyme activity, suggesting that the isolate would potentially be a good source of BSH.
Conventional doxorubicin, a drug commonly used to treat various types of cancer is limited by its... more Conventional doxorubicin, a drug commonly used to treat various types of cancer is limited by its potential in causing various severe side effects including cardiomyopathy and infusion-related reactions. This study aimed to develop a lipid-based (liposome) formulation of doxorubicin using natural oil bodies from Philippine coconut, Cocos nucifera L. as liposome substitute to ameliorate the toxic effect of the drug while maintaining its efficacy. Water with phospholipid from coconut oil bodies at ~5-20mg/ml were mixed with cholesterol to modulate membrane permeability and biological stability. Liposomes were prepared via active lipid based encapsulation of doxorubicin using ammonium sulfate loading procedure of 120 mM ammonium sulfate, pH 5.5, and outside buffer exchanged to 145 mM sodium chloride, pH 5.5 to establish an ion-gradient. In preparing liposomal doxorubicin, critical parameters were checked including liposomal lipid concentration, drug concentration, encapsulation efficiency, liposomal size and pH gradient after drug loading. These results suggest that targeted pH-sensitive lipid based formulation of doxorubicin using natural oil bodies sourced from Philippine coconuts have the potential to globally compete with commercially available liposomal doxorubicin formulations in marginalizing the cost of cancer treatment in enhancing the therapeutic efficacy and targeted delivery of doxorubicin.
Doxorubicin (DOX) is a common chemotherapeutic drug in treatment with various types of cancer cel... more Doxorubicin (DOX) is a common chemotherapeutic drug in treatment with various types of cancer cells. However, its efficacy is limited by undesirable side-effects, which are partially caused by its non-specific delivery to the cancer cells target site. This study aimed to formulate a pH-responsive lipid-based encapsulation of DOX done through self-assembly method by introducing the isolated oil bodies from Philippine coconut oil together with DOX through simultaneous sonication and freeze-thawing, and to study the in vitro cytotoxicity of formulated lipid-based encapsulated DOX on fibroblast and cancer cell lines of humans. Our results show that lipid-based encapsulated DOX can enhance the cytotoxicity, biocompatibility, release profile, and selectivity of DOX in targeting specific cancer cells, hence, enhancing the therapeutic efficacy and targeted delivery of DOX using coconut oil bodies as encapsulating material.
The Philippine coconut, Cocus nucifera L. is a common natural product commercially available thro... more The Philippine coconut, Cocus nucifera L. is a common natural product commercially available throughout the country. The ready availability of coconut in the market proves its own value for research. Extracted coconut meat was mixed and filtered with sodium phosphate buffers with different concentrations of sucrose. Natural oil bodies were assembled in PBS with coconut oil, phospholipid from lecithin, and purified Oleosin. Two assemblies were made, the first assembly contained Oleosin, while the second assembly was washed with urea to remove the oleosin. The mixtures were subjected to sanitation and freezing thrice, and placed at room temperature for self-assembly. During the course of preparation, parameters of oil body encapsulation were compared with those of lipomixture. There parameters included primarily pH gradient, liposomal size, encapsulation efficiency. Results suggest that products such as Oil bodies and oleosin isolated and purified from coconut have a potential encapsulation usage for Doxorubicin drug. Also, lipid based formulation of doxorubicin using natural oil bodies that are sourced from Philippine Coconuts are comparable with the commercially available liposomal doxorubicin formulation. Thus, a potential readily available and cheap substitute is on its way.
Probiotics are live microorganisms that confer health benefits to humans. Microencapsulation prov... more Probiotics are live microorganisms that confer health benefits to humans. Microencapsulation provides multiple protection for improved stability, viability and delivery int the body. Probiotic microorganisms such as Bifidobacteria, Lactobacillus and Streptococcus thermophiles from DUOLACTM was microencapsulated using natural oil emulsions from Philippine coconut species. In this study, oil bodies from coconut were obtained using sucrose gradient separation and purified by floatation centrifugation. Microencapsulation using emulsion technique was performed using Ultra-Turrax homogenizer and optimized at various parameters such as concentration of oil bodies as emulsifying agent, speed and duration of homogenization. Freeze-dried samples were tested to survive in gastric and intestinal pH conditions at 24, 48 and 72 hours. Viability of microencapsulated probiotics from DUOLACTM was assessed using Alamar blue. Particle size and morphology of the microcapsules were determined using digital polarized microscope. Desirable microcapsule size (10um) was obtained from 1:20 coconut oil concentration at 10,000 rpm using Ultra-Turrax homogenizer at high degree of viability. The release of probiotic material was found to be slower in acidic gastric pH and faster in the neutral intestinal pH where it is needed. Prolonged viability of probiotics was observed in both gastric and intestinal conditions. The use of coconut oil emulsions has greatly enhanced the DUOLACTM technology for added protection and stability of probiotics for improved absorption and bioavailability.
Methicillin-resistant Staphylococcus aureus (MRSA) is the most prevalent nosocomial infection in ... more Methicillin-resistant Staphylococcus aureus (MRSA) is the most prevalent nosocomial infection in both developing and developed countries. Methicillin resistance is due to the presence of mecA gene which is highly conserved among MRSA strains. The study aims to develop loop-mediated isothermal amplification (LAMP) as a detection method in hospital-associated samples of MRSA (HA-MRSA). A set of four primers were designed based on the mecA gene of MRSA. LAMP parameters such as MgCl2 concentration, denaturation time, incubation time, incubation temperature and primer concentration were optimized. DNA of MRSA and methicillin sensitive Staphylococcus aureus (MSSA) were used as templates for amplification. LAMP products were visualized using agarose gel. Using the optimized LAMP conditions, the assay was used to detect MRSA from clinical samples obtained and authenticated from the Department of Pathology Laboratory in the Armed Forces of the Philippines Medical Center. The LAMP assay was able to detect the mecA gene of MRSA using the designed primers and the optimized conditions. Also, the assay showed a high degree of specificity to MRSA against the sensitive strains. LAMP method is a simple, fast, inexpensive and sensitive tool that can be used to rapidly detect MRSA for routine clinical diagnostics in resource-limited settings.
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Papers by Myla Santiago
and breast cancers. Its use in cancer chemotherapy is limited due to
short plasma circulation, long elimination half-life, and non-specific
cytotoxicity that may affect the normal cells. Thus, we have designed a
drug delivery system, using a naturally occurring anionic polymer that
is used for drug delivery due to its inert nature, high degree of
biocompatibility, low toxicity, inexpensive and mild gelation with
divalent cations such as calcium in forming particles. In this research,
calcium alginate was used to encapsulate doxorubicin and assessed its
compatibility with calcium alginate as drug delivery system. pH
compatibility of alginate particle formation were assessed relative to the affinity of DOX.
Alginate efficiency to encapsulate DOX was also tested and characterized through
morphological analysis of the particles with the use of phase contrast microscope and
scanning electron microscope (SEM). Fourier transform infrared spectrophotometer (FTIR)
was used to confirm if the DOX was able to encapsulate within the alginate particles. Results
showed that alginate encapsulation was compatible with DOX at neutral pH and
encapsulation efficiency was achieved at 99.30%±0.0045 for 10ppm of DOX and
95.16%±0.011 for the 1.25ppm of DOX. An observable DOX-alginate particles with size
average of 100-300μm using phase contrast microscope (40-60X magnification) and scanning
electron microscope (200-300X magnification). DOX release in phosphate buffered saline
(pH 7.2) confirmed that the DOX was successfully encapsulated based in FTIR data with
comparable differences in the functional groups of DOX, alginate, and DOX released from the particles.
polysaccharide found in marine brown algae. It has a long list of use
in numerous drug delivery systems due to its biodegradability and
biocompatibility. The study aimed to encapsulate doxorubicin using
alginate via ionotropic gelation method and assess the capacity of
encapsulated drug to kill breast cancer cells through cell viability
assay. Formulation of alginate-based particles was done through
ionotropic gelation method. Preliminary test include encapsulation of
solution with pH indicators to determine the biocompatibility of
alginate to doxorubicin. The results showed compatibility of calciumalginate
with basic and acidic solutions. Encapsulation of doxorubicin in calcium-alginate
based particles exceeded 90% encapsulation efficiency. The encapsulated drug manifests
a controlled release profile of 7% in PBS pH 7.4 at 37ï‚°C during the first hour. Delayed drug
release is vital in drug delivery system. The capacity of the encapsulated doxorubicin against
free doxorubicin to kill tumor cells was determined by an in vitro cell culture using breast
cancer cells and tests its cell proliferative activity by MTT assay. Trypan Blue Assay showed
the cell density upon delivery of the encapsulated drug decreased as time progressed. While the MTT assay showed that the encapsulated drug can inhibit the breast cancer cells proliferation with a 12.85%, 77.75% and 96.45% inhibition during 20, 40, and 60 hours respectively (p0.050). In that note, encapsulation of doxorubicin in a calcium alginate based particles are proven to be effective in terms of drug delivery, breast cancer cells viability and in minimizing chemoresistance of cells.
Conference Presentations by Myla Santiago
and breast cancers. Its use in cancer chemotherapy is limited due to
short plasma circulation, long elimination half-life, and non-specific
cytotoxicity that may affect the normal cells. Thus, we have designed a
drug delivery system, using a naturally occurring anionic polymer that
is used for drug delivery due to its inert nature, high degree of
biocompatibility, low toxicity, inexpensive and mild gelation with
divalent cations such as calcium in forming particles. In this research,
calcium alginate was used to encapsulate doxorubicin and assessed its
compatibility with calcium alginate as drug delivery system. pH
compatibility of alginate particle formation were assessed relative to the affinity of DOX.
Alginate efficiency to encapsulate DOX was also tested and characterized through
morphological analysis of the particles with the use of phase contrast microscope and
scanning electron microscope (SEM). Fourier transform infrared spectrophotometer (FTIR)
was used to confirm if the DOX was able to encapsulate within the alginate particles. Results
showed that alginate encapsulation was compatible with DOX at neutral pH and
encapsulation efficiency was achieved at 99.30%±0.0045 for 10ppm of DOX and
95.16%±0.011 for the 1.25ppm of DOX. An observable DOX-alginate particles with size
average of 100-300μm using phase contrast microscope (40-60X magnification) and scanning
electron microscope (200-300X magnification). DOX release in phosphate buffered saline
(pH 7.2) confirmed that the DOX was successfully encapsulated based in FTIR data with
comparable differences in the functional groups of DOX, alginate, and DOX released from the particles.
polysaccharide found in marine brown algae. It has a long list of use
in numerous drug delivery systems due to its biodegradability and
biocompatibility. The study aimed to encapsulate doxorubicin using
alginate via ionotropic gelation method and assess the capacity of
encapsulated drug to kill breast cancer cells through cell viability
assay. Formulation of alginate-based particles was done through
ionotropic gelation method. Preliminary test include encapsulation of
solution with pH indicators to determine the biocompatibility of
alginate to doxorubicin. The results showed compatibility of calciumalginate
with basic and acidic solutions. Encapsulation of doxorubicin in calcium-alginate
based particles exceeded 90% encapsulation efficiency. The encapsulated drug manifests
a controlled release profile of 7% in PBS pH 7.4 at 37ï‚°C during the first hour. Delayed drug
release is vital in drug delivery system. The capacity of the encapsulated doxorubicin against
free doxorubicin to kill tumor cells was determined by an in vitro cell culture using breast
cancer cells and tests its cell proliferative activity by MTT assay. Trypan Blue Assay showed
the cell density upon delivery of the encapsulated drug decreased as time progressed. While the MTT assay showed that the encapsulated drug can inhibit the breast cancer cells proliferation with a 12.85%, 77.75% and 96.45% inhibition during 20, 40, and 60 hours respectively (p0.050). In that note, encapsulation of doxorubicin in a calcium alginate based particles are proven to be effective in terms of drug delivery, breast cancer cells viability and in minimizing chemoresistance of cells.