Biology subjects

Lee, I. L.

Publications and source records attributed to Lee, I. L..

3 recordsLinked to original sources

bioRxiv2024

Measurement of covalent bond formation in light-curing hydrogels predicts physical stability under flow

Photocrosslinking hydrogels are promising for tissue engineering and regenerative medicine, but challenges in reaction monitoring often leave their optimization subject to trial and error. The stability of crosslinked gels under fluid flow, as in the case of a microfluidic device, is particularly challenging to predict, both because of obstacles inherent to solid-state macromolecular analysis that prevent accurate chemical monitoring, and because stability is dependent on size of the patterned features. To solve both problems, we obtained 1H NMR spectra of cured hydrogels which were enzymatically degraded. This allowed us to take advantage of the high-resolution that solution NMR provides. This unique approach enabled the measurement of degree of crosslinking (DoC) and prediction of material stability under physiological fluid flow. We showed that NMR spectra of enzyme-digested gels successfully reported on DoC as a function of light exposure and wavelength within two classes of photocrosslinkable hydrogels: methacryloyl-modified gelatin and a composite of thiol-modified gelatin and norbornene-terminated polyethylene glycol. This approach revealed that a threshold DoC was required for patterned features in each material to become stable, and that smaller features required a higher DoC for stability. Finally, we demonstrated that DoC was predictive of the stability of architecturally complex features when photopatterning, underscoring the value of monitoring DoC when using light-reactive gels. We anticipate that the ability to quantify chemical crosslinks will accelerate the design of advanced hydrogel materials for structurally demanding applications such as photopatterning and bioprinting. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/601353v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1aa4a43org.highwire.dtl.DTLVardef@f1b008org.highwire.dtl.DTLVardef@15bf652org.highwire.dtl.DTLVardef@88a825_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

Association of Blastocystis and Gut Microbiota in Type 2 Diabetic Mellitus Patients and Non-Diabetic Individuals.

The influence of anaerobic protozoan Blastocystis on human gut health is not well understood. While Blastocystis species frequently inhabit the gut, their clinical importance and ecological function remain ambiguous. A study on Blastocystis was carried out enrolling a total of 203 participants including T2DM patients and non-diabetic individuals to evaluate the prevalence of Blastocystis and its association in gut microbiota. Blastocystis subtypes were identified by PCR and faecal microbiome was accessed by targeting V4 region of the bacterial 16S ribosomal gene. The prevalence of Blastocystis in T2DM was 25.49% and 17.82% in non-diabetic individuals with the most prevalent subtype on total population was ST3, followed by ST1 and ST2. The composition of gut microbiota was significantly different between Blastocystis-positive and Blastocystis-negative individuals. Blastocystis carriage was positively associated with higher alpha diversity in T2DM patients and non-diabetic individuals. Interestingly, at the phylum level, the T2DM group had an obvious increase of Bacteroidetes and a marked increase of Actinobacteria with the present of Blastocystis. The findings suggested that the presence of Blastocystis was linked to increased diversity and richness in the gut bacterial composition, signifying at a potentially beneficial association between Blastocystis and the gut microbiota. Author SummaryType 2 Diabetes Mellitus Patients (T2DM), a prevalent global disease, affects a significant portion of the population across the world. Thus, there is need to better understanding on Blastocystis infection among T2DM that could lead to the alteration toward gut health. We evaluated the association between Blastocystis and gut microbiota, where involving two groups; T2DM patients and non-Diabetic individuals. The research revealed a higher Blastocystis in T2DM patients compared to non-diabetic individuals, emphasizing on assumption toward its pathogenicity. However, amplicon-based sequencing of 16S rRNA genes indicates that Blastocystis carriers exhibit increased gut microbiota diversity. Our result suggested that, Blastocystis highlighted its potential role as a component of a balanced microbiota. Notably, optimal alteration in Actinobacteria and Bacteroidetes may contribute to the several gut health. Hence, the study could prompt for further exploration regarding of Blastocystis subtypes and gut microbiota specifically in T2DM to propose for more precise assessment of Blastocystis and gut microbial diversity.

microbiology↗

bioRxiv2022

Gut Microbiome of Helminth Infected Indigenous Malaysians Is Context Dependent

While microbiomes in industrialized societies are well characterized, indigenous populations with traditional lifestyles have microbiomes that are more akin to those of ancient humans. However, metagenomic data in these populations remains scarce and the association with soil-transmitted helminth infection status is unclear. Here, we sequenced 650 metagenomes of indigenous Malaysians from 5 villages with different prevalence of helminth infections. Individuals from villages with higher prevalence of helminth infections have more unmapped reads and greater microbial diversity. Microbial community diversity and composition were most strongly associated with different villages and the effects of helminth infection status on the microbiome varies by village. Longitudinal changes in the microbiome in response to albendazole anthelmintic treatment was observed in both helminth infected and uninfected individuals. Inference of bacterial population replication rates from origin of replication analysis identified specific replicating taxa associated with helminth infection. Our results indicated that helminth effects on the microbiota was highly dependent on context and effects of albendazole on the microbiota can be confounding for the interpretation of deworming studies. Furthermore, a substantial quantity of the microbiome remains undescribed and this large dataset from indigenous populations associated with helminth infections should facilitate characterization of the disappearing microbiome from developed industrialized societies.

microbiology↗