Convolutional neural networks for segmentation of FIB-SEM nanotomography data from porous polymer films for controlled drug release

• Phase-separated polymer films are commonly used as coatings around pharmaceutical oral dosage forms (tablets or pellets) to facilitate controlled drug release. A typical choice is to use ethyl cellulose and hydroxypropyl cellulose (EC/HPC) polymer blends. When an EC/HPC film is in contact with water, the leaching out of the water-soluble HPC phase produces an EC film with a porous network through which the drug is transported. The drug release can be tailored by controlling the structure of this porous network. Imaging and characterization of such EC porous films facilitates understanding of how to control and tailor film formation and ultimately drug release. Combined focused ion beam and scanning electron microscope (FIB-SEM) tomography is a well-established technique for high-resolution imaging, and suitable for this application. However, for segmenting image data, in this case to correctly identify the porous network, FIB-SEM is a challenging technique to work with. In this work, we implement convolutional neural networks for segmentation of FIB-SEM image data. The data are acquired from three EC porous films where the HPC phases have been leached out. The three data sets have varying porosities in a range of interest for controlled drug release applications. We demonstrate very good agreement with manual segmentations. In particular, we demonstrate an improvement in comparison to previous work on the same data sets that utilized a random forest classifier trained on Gaussian scale-space features. Finally, we facilitate further development of FIB-SEM segmentation methods by making the data and software used open access. 

Ämnesord

NATURVETENSKAP  -- Kemi -- Polymerkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Polymer Chemistry (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Polymerteknologi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Polymer Technologies (hsv//eng)

NATURVETENSKAP  -- Kemi -- Annan kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Other Chemistry Topics (hsv//eng)

NATURVETENSKAP  -- Matematik (hsv//swe)

NATURAL SCIENCES  -- Mathematics (hsv//eng)

Nyckelord

controlled drug release

convolutional neural networks

deep learning

focused ion beam scanning electron microscopy

image analysis

machine learning

microstructure

polymer films

porous materials

semantic segmentation

alcohol

ethyl cellulose

hydroxypropylcellulose

porous polymer

polymer

water

Article

artificial neural network

comparative study

controlled study

convolutional neural network

data accuracy

electron beam

feature extraction

focused ion beam

image segmentation

kernel method

molecular weight

prediction

scanning electron microscopy

drug release

porosity

Drug Liberation

Neural Networks

Computer

Polymers

controlled drug release

convolutional neural networks

deep learning

focused ion beam scanning electron microscopy

image analysis

machine learning

microstructure

polymer films

porous materials

semantic segmentation

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