Electrothermal soft manipulator enabling safe transport and handling of thin cell/tissue sheets and bioelectronic devices

“Living” cell sheets or bioelectronic chips have great potentials to improve the quality of diagnostics and therapies. However, handling these thin and delicate materials remains a grand challenge because the external force applied for gripping and releasing can easily deform or damage the materials. This study presents a soft manipulator that can manipulate and transport cell/tissue sheets and ultrathin wearable biosensing devices seamlessly by recapitulating how a cephalopod’s suction cup works. The soft manipulator consists of an ultrafast thermo-responsive, microchanneled hydrogel layer with tissue-like softness and an electric heater layer. The electric current to the manipulator drives microchannels of the gel to shrink/expand and results in a pressure change through the microchannels. The manipulator can lift/detach an object within 10 s and can be used repeatedly over 50 times. This soft manipulator would be highly useful for safe and reliable assembly and implantation of therapeutic cell/tissue sheets and biosensing devices

A review of surgical management of progressive myogenic ptosis

Surgical correction of myogenic ptosis is a sophisticated endeavor, as the disease is progressive and the post-operative course is prone to significant complications. We sought to review the literature for repair techniques in different types of myogenic ptosis. A PubMed/MEDLINE literature search of publications pertaining to surgical outcomes of progressive myogenic ptosis repair was performed. Studies included were original retrospective studies with a minimum of four patients. A total of 27 articles were identified and divided by etiology of myogenic ptosis; either chronic progressive external ophthalmoplegia (CPEO), oculopharyngeal muscular dystrophy (OPMD), myasthenia gravis (MG), or mixed. Surgical techniques predominantly involved levator advancement, levator resection, frontalis sling, blepharoplasty, and Fasanella-Servat. Success rates ranged from 60.5% to 100%. Significant postoperative complications included ptosis recurrence, under-correction, over-correction, keratopathy, lagophthalmos, sling exposure, and sling infection. Like surgical repair for other forms of ptosis, correction of progressive myogenic ptosis is guided by levator excursion. However, myogenic ptosis is especially challenging as it is characterized by worsening ptosis and the loss of protective corneal mechanisms. The goals of care with myogenic ptosis involves repairing ptosis just sufficiently to alleviate visual obstruction while avoiding adverse post-operative complications. This intentional under-correction subsequently increases susceptibility for ptosis recurrence. Myogenic ptosis repair therefore requires delicate balancing between function, sustained repair, and corneal protection.</p

Histatin-1 Expression in Human Lacrimal Epithelium.

BACKGROUND:Study of human lacrimal cell biology is limited by poor access to tissue samples, heterogeneous cell composition of tissue and a lack of established lacrimal epithelial markers. In order to further our understanding of lacrimal cell biology, we sought to find a better marker for human lacrimal epithelial cells, compared to what has been reported in the literature. METHODS:We utilized human Muller's muscle conjunctival resection (MMCR) specimens containing accessory lacrimal gland (ALG) and cadaveric main lacrimal gland (MLG) as sources of lacrimal tissue. Candidate markers were sought using human ALG tissue from MMCR specimens, isolated by laser capture microdissection (LCM). Affymetrix® analysis was performed on total RNA isolated from FFPE samples to profile transcription in ALG. MMCR tissue sections were assessed by immunofluorescence using antibodies for histatin-1, lactoferrin, E-cadherin (E-cad) and alpha-smooth muscle actin (ASMA). Reverse transcriptase polymerase chain reaction (RT-PCR) analysis was performed to analyze the expression of histatin-1, E-cad and lactoferrin from cadaveric MLG. RESULTS:Histatin-1 is expressed in ALG and MLG, localizes to lacrimal epithelium, and to a greater degree than do other putative lacrimal epithelial markers. CONCLUSIONS:Histatin-1 is a good marker for human lacrimal epithelium in ALG and MLG and can be used to identify lacrimal cells in future studies

Immunofluorescence staining of cultured MLG cells.

<p>Immunofluorescence staining in cultured MLG cells using antibodies to lactoferrin (Row A), E-cad (Row C), ASMA (Row E) and histatin-1 (Rows A, C, E). Rows B, D and F are respective negative control images. Column 1 depicts a single stain for antibodies to lactoferrin (Rows A) E-cad (Rows C, D), ASMA (Rows E,F). Column 2 shows stain for histatin-1. Column 3 shows an overlapped image of Column 1 and 2 and blue staining for nuclei (DAPI). Row A shows strong localization of lactoferrin and histatin-1 to cultured MLG epithelium. Row C shows strong localization of E-cad and histatin-1 to cultured MLG epithelium. Row E shows strong localization of histain-1 to cultured MLG epithelium but ASMA does not localize well to cultured MLG epithelium. Scale bar, 50 μm.</p

Important gene in ALG function.

<p>Important gene in ALG function.</p

LASER Capture Microdissection of Accessory Lacrimal Gland.

<p>LCM of ALG from FFPE Human MMCR specimens. (A) Intact ALG in an MMCR specimen (white arrow). (B, C) LASER dissection of ALG from MMCR D. Isolated ALG tissue.</p

Important stem cell genes expression in ALG.

<p>Important stem cell genes expression in ALG.</p

Primer Sequences.

<p>Primer Sequences.</p