Device for inducing cell permeability in a portion of tissue by opto-poration

Abstract

A device for inducing cell. permeability in a portion of tissue by opto-poration comprising' an elongate body (2) along an axis H provided with a first tapered cutting end (3) shaped to pierce the skin and / or the underlying tissue and be inserted into a portion (F) of tissue; the elongated body (2) is of the tubular type and defines an internal cavity (4) defined by a side wall (5) and is provided with at least one opening (6) made on the side wall (5) and arranged at a predetermined distance from the tapered cutting end (3). The elongated body houses in the cavity (4) a waveguide (7) configured to convey a laser beam fed in input to the waveguide and a side™ emitting deflection device (8) adapted to vary the direction of propagation of the laser beam so that the laser beam exits from the opening (6) propagating transversely to the axis (H) so as to impinge the portion of tissue (F) arranged around the elongated body (2)

Description

[0001] "DEVICE FOR INDUCING CELL PERMEABILITY IN A PORTION OF TISSUE BY

[0002] OPTO-PORATION"

[0003] Technical Field

[0004] The present invention relates to a device for inducing cell permeability in a portion of tissue by opto-poration .

[0005] Background of the invention

[0006] Opto-poration involves the temporary and reversible permeabilisation of the lipid membranes of the cells by means of high intensity light (usually generated by laser) while leaving the other internal cell structures intact so as to preserve cell function and viability . The main purpose of opto-poration is to facilitate the introduction of molecules into the cells, which is why it is used to assist the controlled local-regional or systemic release of drugs .

[0007] The mechanisms of permeabilisation of the cell membrane by laser are based on the absorption of electromagnetic energy by the cell membrane itself or by another absorbing agent placed close to it .

[0008] The absorption of electromagnetic energy can give rise to complex ef fects involving combinations of mechanical, thermal and chemical effects .

[0009] Specifically, direct opto-poration occurs when the permeabilisation of the lipid membrane results from the direct interaction of a focal region of the laser with the membrane, which in this case constitutes the absorbing agent .

[0010] Mediated opto-poration procedures are also envisaged in which the permeabilisation of the lipid membrane occurs as a result of absorption of the energy generated by the laser by an absorbing agent in contact with or near the cell (such as a particle or surface) , which generates secondary effects on the membrane .

[0011] Recent studies on opto-poration report the use of lasers with wavelengths greater than 700 nm that offer high accuracy and high- frequency spatial resolution (range •MHz) and pulse times of the order of femtoseconds with cumulative exposure on the order of milliseconds or less (Stewart, M. P. , Langer, R. , & Jensen, K. F. (2018) .

[0012] Intracellular delivery by membrane disruption : mechanisms, strategies, and concepts . Chemical reviews, 118 (16) , 7409-7531. ) .

[0013] For example, patent US2013052725A1 describes a system for opto- poration comprising: a support for containing exogenous cells and molecules; an infrared (IR) light source that generates an IR optical beam and one or more focusing elements; an imaging device; a processor that generates a signal corresponding to a cell localization; and a light pattern shaper that is configured to temporally and spatially shape the optical beam on the cells for a period of time adapted to permeabilise the cell membrane .

[0014] Opto-poration of cells is achieved in known methods in a superficial manner by having the laser impinge on a tissue surface on which the cells are located, and for this reason deep tissue optoporation is not possible .

[0015] In this way, opto-poration procedures are limited by the precise placement of the laser focal point on the surface . An incorrect focus of a few pm results in a significant reduction in the efficiency of lipid membrane breakdown .

[0016] Aim of the present invention Aim of the present invention is to generate and use the phenomenon of the opto-poration in depth in a portion of tissue .

[0017] The foregoing aim is achieved by the present invention in that it relates to a device for inducing cell permeability in a portion of tissue by opto-poration of the type described in Claim 1 .

[0018] Brief description of the drawings

[0019] The invention will now be shown with reference to the accompanying drawings which represent a non-limiting embodiment in which :

[0020] Figure 1 shows in side view a device for inducing cell permeability in a portion of tissue by opto-poration realized according to the present invention;

[0021] Figure 2 shows a detail of the light deflection device 3 for opto-poration treatment of a portion of the human body shown in

[0022] Figure 1 ;

[0023] Figure 3 shows an example of wavelengths that can be used with the device according to the present invention;

[0024] Figure 4 shows a variant to the device shown in Figure 1; and

[0025] Figure 5 shows a plurality of devices according to the present invention used in an arrayed electrode .

[0026] Preferred embodiment example

[0027] In Figure 1, number 1 denotes a device for inducing cell permeability in a portion of tissue by opto-poration realized in accordance with the present invention .

[0028] The device 1 is needle-shaped and comprises an elongated body

[0029] 2 along an axis H provided with a first tapered cutting end 3 configured to pierce the skin S and the underlying tissues M with minimal trauma and be inserted into a portion F of human body . The elongated body 2 is of tubular type and defines an internal cavity 4 coaxial to the axis H defined by a cylindrical wall 5 of the body 2; the internal cavity 4 communicates with the outside of the elongated body 2 through at least one opening 6 made at a second end of the elongated body 2. In the example shown in Figure 1, two elongated openings 6 are provided along the axis H and arranged on opposite sides of the cylindrical wall 5. The opening 6 is then made on the cylindrical wall 5 and arranged at a predetermined distance from the tapered cutting end 3. In the example shown in Figure 1, the opening 6 is approximately rectangular with the longer sides arranged parallel to the axis H . It is clear, however, that the opening 6 can have any shape and dimension and can be placed in any position along the body 2. The number of openings 6 is also variable

[0030] (at least one opening 6 must be provided) . The opening 6 may be provided with a transparent closing and protective wall 6a, for example made of glass or polymer; examples of polymers that may be used are Poly (2-hydroxyethyl methacrylate) (pHEMA) , polymethyl methacrylate (PMMA) , siloxanes and hydrogel . The closing and protective wall can also be made of poly (lactic-co-glycolic) acid

[0031] (PLGA) , which is known to be a copolymer used in many Food and Drug

[0032] Administration (FDA) -approved therapeutic devices thanks to its biodegradability and biocompatibility .

[0033] According to the present invention, the elongated body 2 accommodates in the cavity 4 a waveguide 7 adapted to convey along the axis H a laser beam fed in input to the waveguide 7 and a deflection device 8 adapted to vary the direction of propagation of the laser beam so that the laser beam exits from the opening 6 propagating along a direction T transversal to the axis H so as to impinge, in use, the portion of tissue F arranged around the elongated body 2 .

[0034] The waveguide 7 is an optical fibre provided with a first end connected to a laser beam generating device 10 (of a known type shown schematically) and with a second end stably inserted into the elongated body 2 and producing precisely the waveguide 7.

[0035] As is well known, an optical fibre is a waveguide of dielectric material typically consisting of a cylindrical core surrounded by a cladding that has a different refractive index . The optical fibre confines the electromagnetic energy in the form of light within the core and guides the light in a direction parallel to its axis .

[0036] According to the present invention (Figure 2) , the optical fibre

[0037] 7 is of the Side-Emitting Optical Fibers type (SEOF) and the deflection device 8 is realized by dispersion materials or structures arranged or realized in the core or in the cladding of the fibre to achieve the diffusion of light from the core to the cladding and therefore along the transverse direction T through the opening 6.

[0038] For example, the optical fibre known by the trade name Fibrance™ of the manufacturer Corning can be used, which can emit light laterally on sections with length nominally ranging from 0. 5 cm to 10 metres, over a wide wavelength range . The optical fibre 7 is characterised by an extremely reduced diameter, typically a few hundred pm .

[0039] In use, the device 1 or a plurality of devices 1 are inserted into a portion of tissue to be treated so that the end portions 3 are inserted into that portion of tissue. This operation can be carried out under local anaesthesia . The laser beam generating device

[0040] 10 is thus activated so that each device 1 directs the laser beam transversely to the axis H and hits the cells present in the tissue portion . Conveniently, the laser beam generating device produces a laser beam with a wavelength ranging between 500 and ~1500nm, i . e . in the region ranging from orange in the visible spectrum to near infrared (NIR) .

[0041] In more detail, as far as the operating wavelengths are concerned, the optimal range falls within the so-called "Therapeutic

[0042] Window" , i . e . the range in which (Figure 3) the main components present within the tissues of the human body (water, blood, fat) exhibit a minimum of absorption, ensuring at the same time the maximum distance covered by the light propagating within the tissues, and the minimum damage suffered by the tissues themselves in the regions close to the device 1 .

[0043] Depending on the type of light-tissue interaction to be exploited, it is necessary to manage both the power density delivered and the duration of the exposure in a combined manner . In addition, during exposure, the power can be supplied both in continuous mode and in pulsed mode with pulse duration that can be pushed up to the second femur [see for example : Tuchin, V. V. (2003) . Light-tissue interactions . Biomedical Photonics Handbook, 3-1. ] .

[0044] The preferable exploitation regime is the one in which only

[0045] ' thermal effects ' are involved in order to minimise non-reversible damage to cells . To this end, the tissue portion must be provided with power densities that can vary from a minimum of the order of

[0046] W / cm2 to a maximum of the order of MW / cm2, in time intervals that fall within a range going from the order of ms to the order of minutes . Power density, exposure time and pulse duration will be appropriately dimensioned in order to achieve a given temperature in a precise region of the tissue, also taking into account the actual arrangement of the device 1. Power densities higher than

[0047] MW / cmsmay give rise to other non-reversible effects such as photoablation and photo-disgregation .

[0048] Variants of the device described above are possible .

[0049] The device 1 could comprise several optical fibres ( for example, two optical fibres 7a and 7b as shown in Figure 4) housed in the cavity 4 (or in respective parallel cavities 4a, 4b) and each provided with a respective side-emitting deflection device 8 adapted to vary the direction of propagation of the laser beam so that the laser beam exits from a respective opening 6a, 6b made in the cylindrical wall propagating along a direction T transversal to the axis H so that laser beams are produced which impinge on different portions of tissue . Such optical fibres 7a, 7b are connected with respective outputs of laser beam generating device 10a of a laser treatment apparatus configured to provide the optical fibres 7a and

[0050] 7b with light at different wavelengths and / or power densities . In addition, the operating regime. in terms of pulse duration and exposure time, may be different for each of the fibres 7a, 7b used.

[0051] The elongated body 2 could be provided with a capillary hole

[0052] (or more) for drug administration extending along the axis H and provided with a delivery opening that opens onto the cylindrical wall 5 or onto the tapered wall 3; in this case the elongated body

[0053] 2 is provided with seats for housing the fibres and seats for the drug delivery . In this case, the transparent closing and protective wall 6a could be made of a material adapted to transmit light and at the same time releasing a drug by using hydrogel . Several opening

[0054] 6 could be made, each of which has a different distance from the end 3 and is associated with a respective deflection device; the openings

[0055] 6 could be arranged aligned along the axis H .

[0056] The final device could consist of a number of needles greater than one; in this case, an arrayed electrode is made comprising a support structure 11 that keeps each device 1 in a stable position with respect to the other devices 1 while also maintaining the parallelism between the axes H . The number and the spatial arrangement of the devices 1 depend on the extension of the region to be treated and the type of tissue .

[0057] Numbers

[0058] 1 device for inducing cell permeability in a portion of tissue by opto-poration .

[0059] 2 elongated body.

[0060] 3 tapered cutting edge .

[0061] 4 internal cavities .

[0062] 5 cylindrical wall .

[0063] 6 opening .

[0064] 6a transparent closing and protective wall

[0065] 7 waveguide .

[0066] 8 deflection device .

[0067] 10 laser beam generating device

[0068] 11 support structure

Claims

CLAIMS1. - Device for inducing cell permeability in a portion of tissue by opto-poration comprising an elongated body (2) along an axis H provided with a first tapered cutting end (3) shaped to pierce the skin (S) and the underlying tissues (M) and be inserted into a portion (F) of human body tissue; the elongated body (2) is of the tubular type and defines an internal cavity (4 ) delimited by a side wall (5) of the body (2) ; the elongated body (2) is provided with at least one opening( 6) made on the side wall ( 5) and arranged at a predetermined distance from the tapered cutting end (3) , characterized in that the elongated body accommodates in the cavity (4 ) at least one waveguide(7) configured to convey a laser beam fed in input to the waveguide and an at least one deflection device (8) adapted to vary the direction of propagation of the laser beam so that the laser beam exits from the opening (6) propagating along a direction (T) transversal to the axis H so as to impinge the portion of tissue (F) arranged, in use, around the elongated body (2) ; said waveguide (7) is a side-Emitting Optical Fibers (SEOF) type optical fibre and the deflection device (8) is realized by dispersion materials or structures arranged or realized in the core or in the cladding of the optical fibre (7) to achieve the diffusion of the light from the core to the cladding and therefore along the transverse direction (T) .

2. - Device according to Claim 1, wherein the opening (6) is provided with a transparent closing and protective wall (6a) .

3. - Device according to any one of the preceding claims, wherein several optical fibres (7a, 7b) are provided, housed in the cavity(4 ) or in respective cavities and each provided with a respective side-emitting deflection device (8) adapted to vary the direction of propagation of the laser beam so that the laser beam exits from a respective opening (6a, 6b) made in the cylindrical wall, propagating in a direction (T) transversal to the axis H so that laser beams are produced that impinge on different portions of tissue .

4. - Device according to any one of the preceding claims, wherein the elongated body is provided with at least one capillary hole for drug administration extending along the axis H and which is provided with a delivery opening that opens onto the cylindrical wall (5) or onto the tapered wall (3) .

5. - Device according to Claim 4, wherein said opening is closed by a transparent closing and protective wall ( 6a) made of a material adapted to transmit light and at the same time release the drug.

6. - Arrayed electrode comprising a support structure (11 ) carrying a plurality of devices (1) made according to one of Claims1 to 5, the support (11) keeps each device (1 ) in a stable position with respect to the other devices (1 ) while also maintaining parallelism between the axes H .

7. Laser treatment apparatus comprising : a laser beam generating device (10a) ;- a device according to Claim 3, wherein the laser beam generating device (10a) is configured to provide the respective different optical fibres (7a and 7b) with light at different wavelengths and / or power densities and / or, operate different operating regime .

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