Particle sorting methods in microfluidic platforms are gaining momentum for various biomedical applications. Bioparticles are found in different shapes and sizes. However, conventional separation techniques are mainly designed for separation of spherical particles. Thus, there is a need to develop new methods for effective separation of spherical and non-spherical bioparticles for various applications. Deterministic lateral displacement (DLD) microfluidic methods have become popular for high separation resolution, simplicity, and predictability. However, shape sorting in the DLD separation methods is not well researched. Recently, we explored this area and found that pillar shapes in DLD significantly affect bioparticle separation. In this work, we designed a group of different pillar shapes with protrusions and groove structures with the hypothesis that pillar protrusions will induce particle rotation while pillar grooves will confine the particle rotational movement in a directed path for effective separation in a DLD pillar array. Using combinations of protrusions and grooves, 3-dimensional spherical particles, 2-dimensional planar disc-shaped red blood cells and 1-dimensional rod-shaped bacteria were separated and two interesting phenomena were observed. Firstly, the arrangement of pillar protrusions and grooves induces inertial movements, enhancing the separation of spherical particles. Secondly, non-spherical particles experience dominant rotational movements due to the protrusions and grooves which help in changing their orientations. This gives an opportunity to perform efficient separation based on the desired orientation (the longest dimension of the particles) by restricting or containing their movement within a specific DLD path.
This is a case report of a rare clinical entity known as atypical histiocytic granuloma (AHG), which was previously grouped under a broad category known as pseudolymphoma or traumatic eosinophilic granuloma. Less than 15 cases of AHG have been reported until date. AHG poses diagnostic dilemma due to its clinical as well as histopathological appearance where it stimulates malignancy. A proper clinicopathological evaluation is necessary to establish the diagnosis and to avoid overtreatment. In this report, we review previously reported cases in literature and try to establish proper clinicopathological correlation, differential diagnosis and management. These will familiarize clinicians to include AHG in their differential diagnosis as well as for the pathologist to segregate pseudolymphomatous lesion in their proper categories. The role of immunohistochemistry (IHC) has been given prime importance to establish the exact diagnosis. Further in this report, we review different status on lymphoproliferative disorders and advocate the use of IHC in categorizing these lesions upon cell lineage and to establish proper nomenclature for these lesions.
During minimally invasive orthopedic surgeries, surgical intervention is required at two stages; to attain hemostasis and subsequently to implant the bone graft or its substitute. There is an apparent need for a material which can simultaneously control bone bleeding and provide support for bone repair. In this work, a moldable putty, which can be applied to bone defects (usually irregular in shape), was developed to address this need. It comprises of a hemostatic factor thrombin, osteoinductive "yolk-shell" particles containing bone growth factor (BMP-2), and an osteoconductive component hydroxyapatite. The yolk shell particles allowed controlled release of BMP-2 and showed significantly enhanced osteogenic differentiation of C2C12 (mouse myoblast) cells as demonstrated by increased alkaline phosphatase (ALP) activity and relative gene expressions of osteogenic differentiation markers. These particles were assembled into a moldable putty by mixing them with hydroxyapatite and silk fibroin solution (binding agent) supplemented with thrombin. The putty showed non-cytotoxicity, hemostatic ability, sustained release of BMP-2 and induced increased mineralization in C2C12 cells. This putty, if applied to bone defects during surgeries, may help attain hemostasis and may enhance bone repair by providing sustained release of bone growth factors.
Gingival angioleiomyoma are rarely encountered lesions and most of these lesions are excised in toto in view of reactive gingival epulitic lesions. However, due to the vascular nature of these lesions, many a times surgeons experience unexpected hemorrhage and require extensive hemostatic management. A preoperative diagnosis is a must for these lesions and at least color imaging techniques can be utilized to know its vascular nature and preoperative tumor embolization can be done to be on the safer side. Also histopathological dilemma can occur due to the varied types of vascular arrangement in angioleiomyoma or due to simulation of other vascular lesion like hemangiomas, as well as due to similarity with other spindle cell neoplasms. We advocate the use of immunohistochemistry (IHC) to establish the exact diagnosis in such cases. Also due to infrequent reports of angioleiomyoma in such unusual location, we want to record this case for further reference in future.
Infection control and modes of sterilizations are the key factors to avoid cross transmission of infection in the field of dentistry. Transmission of disease or infection is noted with improper sterilization of reused instruments. Dental burs are the most important tool in any endodontic or conservative procedures of teeth involving tooth contouring, restorative filling procedures and endodontic procedures. Hence, the present study is undertaken to assess the efficacy of different methods of sterilization or decontamination which are routinely used in dental clinics.
Poly(N-isopropylacrylamide) (pNIPAM) composite microgels incorporating polypyrrole (PPy) nanoparticles were produced using droplet microfluidics. The composite microgels exhibited site-specific de-swelling-swelling properties that were activated by near-infrared light. Their applications for programmable drug release by pulsed-light control were also demonstrated.
Most bioparticles, such as red blood cells and bacteria, are non-spherical in shape. However, conventional microfluidic separation devices are designed for spherical particles. This poses a challenge in designing a separation device for non-spherical bioparticles, as the smallest dimension of the bioparticle has to be considered, which increases fabrication challenges and decreases the throughput. If current methods do not take into account the shape of non-spherical bioparticles, the separation will be inefficient. Here, to address this challenge, we present a novel technique for the separation of red blood cells as a non-spherical bioparticle, using a new I-shaped pillar arrays design. It takes the shape into account and induces rotational movements, allowing us to leverage on the largest dimension, which increases its separation size. This technique has been used for 100% separation of red blood cells from blood samples in a focused stream, outperforming the conventional pillar array designs.
A 3D porous membrane containing pyramidal microstructures around funnel-like pores is demonstrated as a unique anti-clogging porous membrane for high efficiency sorting and patterning of cells/beads. The membrane exhibits four interesting features: anti-clogging, patterning of micro-entities of different sizes, bi-directional separation and simultaneous separation and patterning of micro-entities.
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